* builtins.c (std_expand_builtin_va_arg): Align operand when needed.

	* i386.c (init_cumulative_args): Set warn_sse; fix handling of variadic
	functions accepting SSE arguments
	(function_arg): Warn only when asked to warn.
	* i386.h (ix86_args): Add warn_sse/warn_mmx fiels.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@75892 138bc75d-0d04-0410-961f-82ee72b054a4