* i386.c (ix86_find_base_term): New.
	* i386-protos.h (ix86_find_base_term): Prototype.
	* i386.h (FIND_BASE_TERM): Define.
	* alias.c (find_base_term): Use it.
	* tm.texi (FIND_BASE_TERM): Document it.

	* alias.c (true_dependence, write_dependence_p): Unchanging
	memory can't conflict with non-unchanging memory.

	* alias.c (memrefs_conflict_p): A BLKmode reference
	to a symbol (or CONST_INT address) always conflicts
	with a reference to another symbol.

From-SVN: r35985