gdb/fortran: add parser support for lbound and ubound

gdb/fortran: add parser support for lbound and ubound

Add support for the LBOUND and UBOUND built in functions to the
Fortran expression parser.

Both support taking one or two arguments.  A single argument, which
must be an array, returns an array containing all of the lower or
upper bound data.

When passed two arguments, the second argument is the dimension being
asked about.  In this case the result is a scalar containing the lower
or upper bound just for that dimension.

Some examples of usage taken from the new test:

  # Given:
  #   integer, dimension (-8:-1,-10:-2) :: neg_array
  #
  (gdb) p lbound (neg_array)
  $1 = (-8, -10)
  (gdb) p lbound (neg_array, 1)
  $3 = -8
  (gdb) p lbound (neg_array, 2)
  $5 = -10

gdb/ChangeLog:

	* f-exp.y (UNOP_OR_BINOP_INTRINSIC): New token.
	(exp): New pattern using UNOP_OR_BINOP_INTRINSIC.
	(one_or_two_args): New pattern.
	(f77_keywords): Add lbound and ubound.
	* f-lang.c (fortran_bounds_all_dims): New function.
	(fortran_bounds_for_dimension): New function.
	(evaluate_subexp_f): Handle FORTRAN_LBOUND and FORTRAN_UBOUND.
	(operator_length_f): Likewise.
	(print_subexp_f): Likewise.
	(dump_subexp_body_f): Likewise.
	(operator_check_f): Likewise.
	* std-operator.def (FORTRAN_LBOUND): Define.
	(FORTRAN_UBOUND): Define.

gdb/testsuite/ChangeLog:

	* gdb.fortran/lbound-ubound.F90: New file.
	* gdb.fortran/lbound-ubound.exp: New file.