PR middle-end/67222
	* gimple-low.c (lower_stmt): Don't lower BUILT_IN_POSIX_MEMALIGN
	if the call isn't valid.
	* tree-ssa-alias.c (ref_maybe_used_by_call_p_1): Check builtins using
	gimple_call_builtin_p.
	(call_may_clobber_ref_p_1): Likewise.
	(stmt_kills_ref_p): Likewise.

	* gcc.dg/torture/pr67222.c: New test.

From-SVN: r226969