PR c++/54777

	* semantics.c (cxx_eval_constant_expression) <case COMPOUND_EXPR>: If
	not ignoring the second operand, pass the original second operand
	and not one with stripped nops to cxx_eval_constant_expression.

	* g++.dg/cpp0x/constexpr-ref4.C: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_7-branch@192037 138bc75d-0d04-0410-961f-82ee72b054a4