* builtins.def (BUILT_IN_VA_ARG_PACK): New built-in.
	* tree.h (CALL_EXPR_VA_ARG_PACK): Define.
	* tree-inline.h (copy_body_data): Add call_expr field.
	* tree-inline.c (expand_call_inline): Initialize call_expr.
	(copy_bb): Append anonymous inline fn arguments to arguments
	when inlining a CALL_EXPR_VA_ARG_PACK call.
	* builtins.c (expand_builtin): Issue an error if
	BUILT_IN_VA_ARG_PACK is seen during expand.
	(fold_call_expr, fold_builtin_call_array): Don't fold
	CALL_EXPR_VA_ARG_PACK CALL_EXPRs or calls with
	__builtin_va_arg_pack () call as last argument.
	* gimplify.c (gimplify_call_expr): If last argument to a vararg
	function is __builtin_va_arg_pack (), decrease number of call
	arguments and instead set CALL_EXPR_VA_ARG_PACK on the CALL_EXPR.
	* expr.c (expand_expr_real_1): Issue an error if
	CALL_EXPR_VA_ARG_PACK CALL_EXPR is seen during expand.
	* tree-pretty-print.c (dump_generic_node): Handle printing
	CALL_EXPR_VA_ARG_PACK bit on CALL_EXPRs.
	* doc/extend.texi (__builtin_va_arg_pack): Document.

	* gcc.c-torture/execute/va-arg-pack-1.c: New test.
	* gcc.dg/va-arg-pack-1.c: New test.

From-SVN: r128150