re PR middle-end/60556 (tip of tree crash with mips compiler)

	PR middle-end/60556
	* expr.c (convert_move): Use emit_store_flag_force instead of
	emit_store_flag.  Pass lowpart_mode instead of VOIDmode as 5th
	argument to it.

	* gcc.c-torture/compile/pr60556.c: New test.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r209300