* system.h (ROUND_UP): New macro definition.
	(ROUND_DOWN): Ditto.
	* ggc-page.c (ROUND_UP): Remove local macro definition.
	(PAGE_ALIGN): Implement using ROUND_UP macro.

	* config/i386/i386.h (PUSH_ROUNDING): Implement using ROUND_UP macro.
	* config/i386/i386.c (function_arg_advance_64): Use ROUND_UP macro
	to align values.
	(ix86_compute_frame_layout): Ditto.
	(ix86_expand_prologue): Ditto.
	(ix86_adjust_stack_and_probe): Use ROUND_DOWN macro
	to round down values.
	(expand_set_or_movmem_via_rep): Ditto.

From-SVN: r228410