re PR rtl-optimization/63475 (Postreload CSE propagates aliased memory operand)

re PR rtl-optimization/63475 (Postreload CSE propagates aliased memory operand)

	PR rtl-optimization/63475
	* alias.c (true_dependence_1): Always use get_addr to extract
	true address operands from x_addr and mem_addr.  Use extracted
	address operands to check for references with alignment ANDs.
	Use extracted address operands with find_base_term and
	base_alias_check. For noncanonicalized operands call canon_rtx with
	extracted address operand.
	(write_dependence_1): Ditto.
	(may_alias_p): Ditto.  Remove unused calls to canon_rtx.

From-SVN: r216217