PR fortran/93366 - ICE on invalid, reject invalid use of NULL() as argument

PR fortran/93366 - ICE on invalid, reject invalid use of NULL() as argument

gcc/fortran/ChangeLog:

2020-05-05  Steve Kargl  <kargl@gcc.gnu.org>
	    Harald Anlauf  <anlauf@gmx.de>

	PR fortran/93366
	* check.c (gfc_check_associated, invalid_null_arg): Factorize
	check for presence of invalid NULL() argument.
	(gfc_check_kind, gfc_check_merge, gfc_check_shape)
	(gfc_check_sizeof, gfc_check_spread, gfc_check_transfer): Use this
	check for presence of invalid NULL() arguments.

gcc/testsuite/ChangeLog:

2020-05-05  Harald Anlauf  <anlauf@gmx.de>

	PR fortran/93366
	* gfortran.dg/pr93366.f90: New test.

(cherry picked from commit 5a26ea7e0f8b9a00a2eb0a5e8f70efa04056f167)