PR rtl-optimization/54900
	* ifcvt.c (noce_can_store_speculate_p): Call
	memory_must_be_modified_in_insn_p.
	* alias.c (memory_must_be_modified_in_insn_p): New.
	(set_dest_equal_p): New.
	* rtl.h (memory_must_be_modified_in_p): Protoize.

From-SVN: r192548