c++: Fix cp_fold_non_odr_use_1 [PR123557,PR123738]

This fixes two issues with cp_fold_non_odr_use_1:

- When called to fold away a reference, it considers the use to not be
  an lvalue and so 'maybe_constant_value' folds all the way through the
  nested INDIRECT_REF to a prvalue.  Fixed by folding the op0 of the
  INDIRECT_REF rather than the ref itself and avoiding a double
  cp_fold_non_odr_use_1.

- When used to fold away the initializing expression for an INIT_EXPR,
  it doesn't mark any new TARGET_EXPRs as eliding.  Fixed by reapplying
  'set_target_expr_eliding' for the initializer of an INIT_EXPR if it
  got modified during ff_only_non_odr walk.

	PR c++/123557
	PR c++/123738

gcc/cp/ChangeLog:

	* cp-gimplify.cc (cp_fold_maybe_rvalue): Call
	cp_fold_non_odr_use_1 before recursing cp_fold.
	(cp_fold): Pass op0 to cp_fold_non_odr_use_1 when folding a
	reference.  Reapply set_target_expr_eliding on the initializing
	expression of an INIT_EXPR.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/constexpr-ice22.C: New test.
	* g++.dg/cpp2a/constexpr-ref2.C: New test.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Jason Merrill <jason@redhat.com>

0 files changed, 0 insertions, 0 deletions