re PR tree-optimization/81620 (ICE in is_inv_store_elimination_chain, at tree-predcom.c:1651 with -O3)

	PR tree-optimization/81620
	* tree-predcom.c (add_ref_to_chain): Don't set has_max_use_after
	for store-store chain.

	gcc/testsuite
	* gcc.dg/tree-ssa/pr81620-1.c: New.
	* gcc.dg/tree-ssa/pr81620-2.c: New.

From-SVN: r250763