re PR target/52991 (attribute packed broken on mingw32?)

re PR target/52991 (attribute packed broken on mingw32?)

	PR target/52991
	* stor-layout.c (update_alignment_for_field): For
	targetm.ms_bitfield_layout_p (rli->t), if !is_bitfield
	&& !DECL_PACKED (field), do the alignment update, just use
	only desired_align instead of MAX (type_align, desired_align)
	as the alignment.
	(place_field): Don't do known_align < desired_align handling
	early if targetm.ms_bitfield_layout_p (rli->t) and rli->prev_field
	is non-NULL, instead do it after rli->prev_field handling and
	only if not within a bitfield word.  For DECL_PACKED (field)
	use type_align of BITS_PER_UNIT.

	* gcc.dg/bf-ms-layout.c: Revert 2012-04-26 changes.
	* gcc.dg/bf-ms-layout-2.c: Revert 2012-02-23 changes.
	* gcc.dg/bf-ms-layout-4.c: New test.
	* gcc.dg/bf-ms-layout-5.c: New test.

From-SVN: r258075