[Ada] Add support for 128-bit fixed-point types on 64-bit platforms

[Ada] Add support for 128-bit fixed-point types on 64-bit platforms

gcc/ada/

	* Makefile.rtl (GNATRTL_NONTASKING_OBJS): Likewise.
	(GNATRTL_128BIT_OBJS): Likewise.
	(GNATRTL_128BIT_PAIRS): Add new 128-bit variants.
	* cstand.adb (Create_Standard): Create Standard_Integer_128.
	* doc/gnat_rm/implementation_defined_characteristics.rst: Document
	new limits on 64-bit platforms in entry for 3.5.9(10).
	* gnat_rm.texi: Regenerate.
	* exp_attr.adb: Add with and use clauses for Urealp.
	(Expand_N_Attribute_Reference) <Attribute_Fore>: Call new routines
	for decimal fixed-point types and common ordinary fixed-point types.
	* exp_ch4.adb (Real_Range_Check): Extend conversion trick to all
	ordinary fixed-point types and use Small_Integer_Type_For.
	* exp_fixd.adb: Add with and use clauses for Ttypes.
	(Build_Divide): Add special case for 32-bit values and deal with
	128-bit types.
	(Build_Double_Divide): Deal with 128-bit types.
	(Build_Double_Divide_Code): Likewise.  Do not apply conversions
	before calling Build_Multiply.
	(Build_Multiply): Likewise.  Add special case for 32-bit values.
	(Build_Scaled_Divide): Deal with 128-bit types.
	(Build_Scaled_Divide_Code): Likewise.  Fix size computation.  Do not
	apply conversions before calling Build_Multiply.
	(Do_Multiply_Fixed_Fixed): Minor tweak.
	(Integer_Literal): Deal with 128-bit values.
	* exp_imgv.adb (Has_Decimal_Small): Delete.
	(Expand_Image_Attribute): Call new routines for common ordinary
	fixed-point types.
	(Expand_Value_Attribute): Likewise.
	(Expand_Width_Attribute): Add new expansion for fixed-point types.
	* freeze.adb (Freeze_Entity): Move error checks for ordinary
	fixed-point types to...
	(Freeze_Fixed_Point_Type): ...here.  Deal with 128-bit types and
	adjust limitations for 32-bnt and 64-bit types.
	* rtsfind.ads (RTU_Id): Add entries for new System_Fore, System_Img,
	and System_Val units and remove them for obsolete units.
	(RE_Id): Add entries for Double_Divide128, Scaled_Divide128, the new
	Fore, Image, Value routines and remove them for obsolete units.
	(RE_Unit_Table): Likewise.
	* sem_ch3.adb (Decimal_Fixed_Point_Type_Declaration): Deal with
	128-bit types.
	* stand.ads (Standard_Entity_Type): Add Standard_Integer_128.
	* uintp.ads (Uint_31): New deferred constant.
	(Uint_Minus_18): Likewise.
	(Uint_Minus_31): Likewise.
	(Uint_Minus_76): Likewise.
	(Uint_Minus_127): Likewise.
	* urealp.ads (Ureal_2_31): New function.
	(Ureal_2_63): Likewise.
	(Ureal_2_127): Likewise.
	(Ureal_2_M_127): Likewise.
	(Ureal_2_10_18): Likewise.
	(Ureal_M_2_10_18): Likewise.
	(Ureal_9_10_36): Likewise.
	(Ureal_M_9_10_36): Likewise.
	(Ureal_10_76): Likewise.
	(Ureal_M_10_76): Likewise.
	(Ureal_10_36): Delete.
	(Ureal_M_10_36): Likewise.
	* urealp.adb (UR_2_10_18): New variable.
	(UR_9_10_36): Likewise.
	(UR_10_76): Likewise.
	(UR_M_2_10_18): Likewise.
	(UR_M_9_10_36): Likewise.
	(UR_M_10_76): Likewise.
	(UR_2_31): Likewise.
	(UR_2_63): Likewise.
	(UR_2_127): Likewise.
	(UR_2_M_127): Likewise.
	(UR_10_36): Delete.
	(UR_M_10_36): Likewise.
	(Initialize): Initialize them.
	(UR_Write): Do not use awkward Ada literal style.
	(Ureal_2_10_18): New function.
	(Ureal_9_10_36): Likewise.
	(Ureal_10_76): Likewise.
	(Ureal_2_31): Likewise.
	(Ureal_2_63): Likewise.
	(Ureal_2_127): Likewise.
	(Ureal_2_M_127): Likewise.
	(Ureal_M_2_10_18): Likewise.
	(Ureal_M_9_10_36): Likewise.
	(Ureal_10_76): Likewise.
	(Ureal_M_10_76): Likewise.
	(Ureal_10_36): Delete.
	(Ureal_M_10_36): Likewise.
	* libgnat/a-decima__128.ads: New file.
	* libgnat/a-tideau.ads, libgnat/a-tideau.adb: Reimplement as
	generic unit.
	* libgnat/a-tideio.adb: Reimplement.
	* libgnat/a-tideio__128.adb: New file.
	* libgnat/a-tifiau.ads, libgnat/a-tifiau.adb: New generic unit.
	* libgnat/a-tifiio.adb: Move bulk of implementation to s-imagef
	and reimplement.
	* libgnat/a-tifiio__128.adb: New file.
	* libgnat/a-tiflau.adb (Get): Minor consistency fix.
	(Gets): Likewise.
	* libgnat/a-wtdeau.ads, libgnat/a-wtdeau.adb: Reimplement as
	generic unit.
	* libgnat/a-wtdeio.adb: Reimplement.
	* libgnat/a-wtdeio__128.adb: New file.
	* libgnat/a-wtfiau.ads, libgnat/a-wtfiau.adb: New generic unit.
	* libgnat/a-wtfiio.adb: Reimplement.
	* libgnat/a-wtfiio__128.adb: New file.
	* libgnat/a-ztdeau.ads, libgnat/a-ztdeau.adb: Reimplement as
	generic unit.
	* libgnat/a-ztdeio.adb: Reimplement.
	* libgnat/a-ztdeio__128.adb: New file.
	* libgnat/a-ztfiau.ads, libgnat/a-ztfiau.adb: New generic unit.
	* libgnat/a-ztfiio.adb: Reimplement.
	* libgnat/a-ztfiio__128.adb: New file.
	* libgnat/g-rannum.adb (Random_Decimal_Fixed): Use a subtype of the
	appropiate size for the instantiation.
	(Random_Ordinary_Fixed): Likewise.
	* libgnat/s-arit32.ads, libgnat/s-arit32.adb: New support unit.
	* libgnat/s-fode128.ads: New instantiation.
	* libgnat/s-fode32.ads: Likewise.
	* libgnat/s-fode64.ads: Likewise.
	* libgnat/s-fofi128.ads: Likewise.
	* libgnat/s-fofi32.ads: Likewise.
	* libgnat/s-fofi64.ads: Likewise.
	* libgnat/s-fore_d.ads, libgnat/s-fore_d.adb: New generic unit.
	* libgnat/s-fore_f.ads, libgnat/s-fore_f.adb: Likewise.
	* libgnat/s-fore.ads, libgnat/s-fore.adb: Rename into...
	* libgnat/s-forrea.ads, libgnat/s-forrea.adb: ...this.
	* libgnat/s-imaged.ads, libgnat/s-imaged.adb: New generic unit.
	* libgnat/s-imagef.ads, libgnat/s-imagef.adb: Likewise, taken
	from a-tifiio.adb.
	* libgnat/s-imde128.ads: New instantiation.
	* libgnat/s-imde32.ads: Likewise.
	* libgnat/s-imde64.ads: Likewise.
	* libgnat/s-imfi128.ads: Likewise.
	* libgnat/s-imfi32.ads: Likewise.
	* libgnat/s-imfi64.ads: Likewise.
	* libgnat/s-imgdec.ads, libgnat/s-imgdec.adb: Delete.
	* libgnat/s-imglld.ads, libgnat/s-imglld.adb: Likewise.
	* libgnat/s-imgrea.adb (Set_Image_Real): Replace Sign local variable
	with Minus local variable for the sake of consistency.
	* libgnat/s-imguti.ads, libgnat/s-imguti.adb: New support unit.
	* libgnat/s-vade128.ads: New instantiation.
	* libgnat/s-vade32.ads: Likewise.
	* libgnat/s-vade64.ads: Likewise.
	* libgnat/s-vafi128.ads: Likewise.
	* libgnat/s-vafi32.ads: Likewise.
	* libgnat/s-vafi64.ads: Likewise.
	* libgnat/s-valdec.ads, libgnat/s-valdec.adb: Delete.
	* libgnat/s-vallld.ads, libgnat/s-vallld.adb: Likewise.
	* libgnat/s-valued.ads, libgnat/s-valued.adb: New generic unit.
	* libgnat/s-valuef.ads, libgnat/s-valuef.adb: Likewise.
	* libgnat/s-valuei.adb: Minor rewording.
	* libgnat/s-valrea.adb: Move bulk of implementation to...
	* libgnat/s-valuer.ads, libgnat/s-valuer.adb: ...here.  New
	generic unit.
	* libgnat/system-aix.ads (Max_Mantissa): Adjust.
	* libgnat/system-darwin-arm.ads (Max_Mantissa): Likewise.
	* libgnat/system-darwin-ppc.ads (Max_Mantissa): Likewise.
	* libgnat/system-darwin-x86.ads (Max_Mantissa): Likewise.
	* libgnat/system-djgpp.ads (Max_Mantissa): Likewise.
	* libgnat/system-dragonfly-x86_64.ads (Max_Mantissa): Likewise.
	* libgnat/system-freebsd.ads (Max_Mantissa): Likewise.
	* libgnat/system-hpux-ia64.ads (Max_Mantissa): Likewise.
	* libgnat/system-hpux.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-alpha.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-arm.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-hppa.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-ia64.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-m68k.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-mips.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-ppc.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-riscv.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-s390.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-sh4.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-sparc.ads (Max_Mantissa): Likewise.
	* libgnat/system-linux-x86.ads (Max_Mantissa): Likewise.
	* libgnat/system-lynxos178-ppc.ads (Max_Mantissa): Likewise.
	* libgnat/system-lynxos178-x86.ads (Max_Mantissa): Likewise.
	* libgnat/system-mingw.ads (Max_Mantissa): Likewise.
	* libgnat/system-qnx-aarch64.ads (Max_Mantissa): Likewise.
	* libgnat/system-rtems.ads (Max_Mantissa): Likewise.
	* libgnat/system-solaris-sparc.ads (Max_Mantissa): Likewise.
	* libgnat/system-solaris-x86.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-arm-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-arm-rtp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-arm.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-e500-kernel.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-e500-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-e500-rtp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-e500-vthread.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-ppc-kernel.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-ppc-ravenscar.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-ppc-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-ppc-rtp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-ppc-vthread.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-ppc.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-x86-kernel.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-x86-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-x86-rtp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-x86-vthread.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks-x86.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-aarch64-rtp-smp.ads (Max_Mantissa):
	Likewise.
	* libgnat/system-vxworks7-aarch64.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-arm-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-arm.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-e500-kernel.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-e500-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-e500-rtp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-ppc-kernel.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-ppc-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-ppc-rtp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-ppc64-kernel.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-ppc64-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-x86-kernel.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-x86-rtp-smp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-x86-rtp.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-x86_64-kernel.ads (Max_Mantissa): Likewise.
	* libgnat/system-vxworks7-x86_64-rtp-smp.ads (Max_Mantissa): Likewise.

gcc/testsuite/

	* gnat.dg/multfixed.adb: Robustify.