mt.md (decrement_and_branch_until_zero): Add another scratch.

mt.md (decrement_and_branch_until_zero): Add another scratch.

	* config/mt/mt.md (decrement_and_branch_until_zero): Add another
	scratch.  Correct its reload split. Adjust its peephole.
	(doloop_end): Add additional scratch.
	(nop): Use 'nop'.
	* config/mt/mt.c (MT_INT_ARG_FIRST): Remove.
	(mt_asm_output_opcode, mt_print_operand): Use 'nop'.
	(mt_function_arg_slotno): Use FIRST_ARG_REGNUM.
	(mt_builtin_saveregs): Replace with ...
	(mt_setup_incoming_varargs): ... here.  Save just the varadic
	args.
	(mt_va_start): Remove.
	(mt_reorg_hazard): Ignore USE insns.  Don't call set_noop_p.
	(mt_machine_reorg): Split all insns here.
	(TARGET_SETUP_INCOMING_VARARGS): Override.
	* config/mt/mt.h (TARGET_CPU_CPP_BUILTINS): Define __mt__ only.
	Set to CPU type.
	(EXPAND_BUILTIN_VA_START): Remove.

From-SVN: r108787