ChangeLog:

	* config/s390/s390.c (GP_ARG_NUM_REG, FP_ARG_NUM_REG): New defines.
	(s390_function_arg, s390_gimplify_va_arg): Use them.
	(s390_register_info): Save only required subset of argument
	registers into save area for va_list.
	(s390_va_start): Initialize only required elements of va_list struct.
	(s390_build_builtin_va_list): Set va_list_[gf]pr_counter_field.

testsuite/ChangeLog:

	* gcc.dg/tree-ssa/stdarg-2.c: Add tests for s390*-*-linux* targets.
	* gcc.dg/tree-ssa/stdarg-3.c: Likewise.
	* gcc.dg/tree-ssa/stdarg-4.c: Likewise.
	* gcc.dg/tree-ssa/stdarg-5.c: Likewise.

From-SVN: r100164