i386.c (struct machine_function): Add save_varrargs_registers.

i386.c (struct machine_function): Add save_varrargs_registers.

	* i386.c (struct machine_function): Add save_varrargs_registers.
	(ix86_save_varrargs_registers): New macro.
	(ix86_frame_layout): Support 64bit; support red zones and varrargs area.
	(ix86_expand_prologue): Likewise.
	(ix86_emit_epilogue_esp_adjustement): Likewise.
	(ix86_expand_epilogue): Likewise.
	* i386.md (pro_epilogue_adjust_stack): Turn to expander; support 64bit.
	(pro_epilogue_adjust_stack_1): New insn.
	(pro_epilogue_adjust_stack_rex64): Likewise.
	* i386.h (MASK_NO_RED_ZONE): New constant.
	(TARGET_RED_ZONE): New macro.
	(TARGET_OPTIONS): Add "red-zone" and "no-red-zone"
	(RED_ZONE_SIZE): New constant.
	(RED_ZONE_RESERVE): New constant.

From-SVN: r40846