* calls.c, dse.c, expr.c, function.c: Call targetm.calls.function_arg,
	targetm.calls.function_incoming_arg, and
	targetm.calls.function_arg_advance instead of FUNCTION_ARG,
	FUNCTION_INCOMING_ARG, and FUNCTION_ARG_ADVANCE, respectively.
	* target.h (struct gcc_target): Add function_arg_advance,
	function_arg, and function_incoming_arg fields.
	* target-def.h (TARGET_FUNCTION_ARG_ADVANCE, TARGET_FUNCTION_ARG):
	(TARGET_FUNCTION_INCOMING_ARG): Define.
	(TARGET_CALLS): Add TARGET_FUNCTION_ARG_ADVANCE, TARGET_FUNCTION_ARG,
	and TARGET_FUNCTION_INCOMING_ARG.
	* targhooks.h (default_function_arg_advance): Declare.
	(default_function_arg, default_function_incoming_arg): Declare.
	* targhooks.c (default_function_arg_advance): New function.
	(default_function_arg, default_function_incoming_arg): New function.
	* config/i386/i386.c (function_arg_advance): Rename to...
	(ix86_function_arg_advance): ...this.  Make static.
	(function_arg): Rename to...
	(ix86_function_arg): ...this.  Make static.
	(TARGET_FUNCTION_ARG_ADVANCE): Define.
	(TARGET_FUNCTION_ARG): Define.
	* config/i386/i386.h (FUNCTION_ARG_ADVANCE): Delete.
	(FUNCTION_ARG): Delete.
	* config/i386/i386-protos.h (function_arg_advance): Delete prototype.
	(function_arg): Delete prototype.

From-SVN: r161530