Fortran: improve check of arguments to the RESHAPE intrinsic

Fortran: improve check of arguments to the RESHAPE intrinsic

gcc/fortran/ChangeLog:

	PR fortran/103411
	* check.c (gfc_check_reshape): Improve check of size of source
	array for the RESHAPE intrinsic against the given shape when pad
	is not given, and shape is a parameter.  Try other simplifications
	of shape.

gcc/testsuite/ChangeLog:

	PR fortran/103411
	* gfortran.dg/pr68153.f90: Adjust test to improved check.
	* gfortran.dg/reshape_7.f90: Likewise.
	* gfortran.dg/reshape_9.f90: New test.