* alias.c: (mark_constant_function): Don't check pure functions.
	Initialize and end alias analysis.
	(nonlocal_mentioned_p): Rename from nonlocal_reference_p.
	Don't make a special exception for recursion.  Handle
	UNSPEC_VOLATILE.  Don't assume ASM_OPERANDS is non-local
	unless it's volatile.

	* local-alloc.c (equivalence): New structure.
	(reg_equiv): Define.
	(contains_replace_regs): Remove array and use
	field in reg_equiv.
	(memref_referenced_p): Likewise.
	(no_equiv): Likewise.
	(update_equiv_regs): Likewise.

	(equiv_init_varies_p,
	equiv_init_movable_p): New functions.
	(update_equiv_regs): Use them.  Use rtx_varies_p
	instead of function_invariant_p.  Process insns
	from end to beginning.  Allow a REG_EQUIV insn
	within the same loop as a use to be moved, also
	allow it to be moved out of a loop.  Update
	REG_DEAD notes when substituting into an insn.

From-SVN: r36957