arc: Add new LD tests for ARCv3.

arc: Add new LD tests for ARCv3.

Add new linker tests for ARCv3 ISA. All the new tests are added in a
distinct new folder named arc64.

ld/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* ld/testsuite/ld-arc64/arcv3_64-reloc-near-exe.dd: New file.
	* ld/testsuite/ld-arc64/arcv3_64-reloc-near-so.dd: Likewise.
	* ld/testsuite/ld-arc64/arcv3_64-reloc-near.s: Likewise.
	* ld/testsuite/ld-arc64/arcv3_64.exp: Likewise.
	* ld/testsuite/ld-arc64/bl34.dd: Likewise.
	* ld/testsuite/ld-arc64/bl34.s: Likewise.
	* ld/testsuite/ld-arc64/linkscript.ld: Likewise.
	* ld/testsuite/ld-arc64/plt34-got.dd: Likewise.
	* ld/testsuite/ld-arc64/plt34-got.s: Likewise.
	* ld/testsuite/ld-arc64/plt34-reloc.dd: Likewise.
	* ld/testsuite/ld-arc64/plt34-reloc.s: Likewise.

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>