Fortran: improve checking of array specifications

gcc/fortran/ChangeLog:

	PR fortran/103505
	* array.c (match_array_element_spec): Try to simplify array
	element specifications to improve early checking.
	* expr.c (gfc_try_simplify_expr): New.  Try simplification of an
	expression via gfc_simplify_expr.  When an error occurs, roll
	back.
	* gfortran.h (gfc_try_simplify_expr): Declare it.

gcc/testsuite/ChangeLog:

	PR fortran/103505
	* gfortran.dg/pr103505.f90: New test.

Co-authored-by: Steven G. Kargl <kargl@gcc.gnu.org>