stor-layout.c (place_union_field): Apply ADJUST_FIELD_ALIGN to type_align when PCC_BITFIELD_TYPE_MATTERS.

	* stor-layout.c (place_union_field): Apply ADJUST_FIELD_ALIGN
	to type_align when PCC_BITFIELD_TYPE_MATTERS.  Only apply
	ADJUST_FIELD_ALIGN if not DECL_USER_ALIGN resp. TYPE_USER_ALIGN.
	(place_field): Likewise.
	* config/i386/i386.c (x86_field_alignment): Don't check
	DECL_USER_ALIGN here.
	* config/rs6000/rs6000.c (rs6000_field_alignment): New.
	* config/rs6000/rs6000-protos.h (rs6000_field_alignment): New
	prototype.
	* config/rs6000/rs6000.h (ADJUST_FIELD_ALIGN): Define.
	* config/rs6000/aix.h (ADJUST_FIELD_ALIGN): Remove.
	* config/rs6000/darwin.h (ADJUST_FIELD_ALIGN): Remove.
	* config/rs6000/linux64.h (ADJUST_FIELD_ALIGN): Remove.
	* config/rs6000/sysv4.h (ADJUST_FIELD_ALIGN): Remove.
	* doc/tm.texi (ADJUST_FIELD_ALIGN): Update description.

	* gcc.dg/i386-bitfield1.c: New test.
	* g++.dg/abi/bitfield3.C: Update.

Co-Authored-By: Richard Henderson <rth@redhat.com>

From-SVN: r56107