PR c++/30274
* cp-tree.h (unlowered_expr_type): New function.
* typeck.c (is_bitfield_expr_with_lowered_type): Handle
COMPOUND_EXPR, MODIFY_EXPR, and SAVE_EXPR.
(unlowered_expr_type): New function.
(build_unary_op): Disallow predecrements of bool bitfields.
* call.c (build_conditional_expr): Use unlowered_expr_type.
* pt.c (type_unification_real): Likewise.
PR c++/30274
* g++.dg/expr/bitfield3.C: New test.
* g++.dg/expr/bitfield4.C: Likewise.
* g++.dg/expr/bitfield5.C: Likewise.
* g++.dg/expr/bitfield6.C: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_2-branch@122814 138bc75d-0d04-0410-961f-82ee72b054a4