re PR fortran/91496 (!GCC$ directives error if mistyped or unknown)

re PR fortran/91496 (!GCC$ directives error if mistyped or unknown)

2019-08-27  Harald Anlauf  <anlauf@gmx.de>

	PR fortran/91496
	* gfortran.h: Extend struct gfc_iterator for loop annotations.
	* array.c (gfc_copy_iterator): Copy loop annotations by IVDEP,
	VECTOR, and NOVECTOR pragmas.
	* decl.c (gfc_match_gcc_ivdep, gfc_match_gcc_vector)
	(gfc_match_gcc_novector): New matcher functions handling IVDEP,
	VECTOR, and NOVECTOR pragmas.
	* match.h: Declare prototypes of matcher functions handling IVDEP,
	VECTOR, and NOVECTOR pragmas.
	* parse.c (decode_gcc_attribute, parse_do_block)
	(parse_executable): Decode IVDEP, VECTOR, and NOVECTOR pragmas;
	emit warning for unrecognized pragmas instead of error.
	* trans-stmt.c (gfc_trans_simple_do, gfc_trans_do): Add code to
	emit annotations for IVDEP, VECTOR, and NOVECTOR pragmas.
	* gfortran.texi: Document IVDEP, VECTOR, and NOVECTOR pragmas.

	PR fortran/91496
	* gfortran.dg/pr91496.f90: New testcase.

From-SVN: r274966