c++: non-static member, array bound, sizeof [PR93314]

c++: non-static member, array bound, sizeof [PR93314]

N2253 allowed referring to non-static data members without an object in
unevaluated operands like that of sizeof, but in a constant-expression
context like an array bound or template argument within such an unevaluated
operand we do actually need a value, so that permission cannot apply.

gcc/cp/ChangeLog:

	PR c++/93314
	* semantics.c (finish_id_expression_1): Clear cp_unevaluated_operand
	for a non-static data member in a constant-expression.

gcc/testsuite/ChangeLog:

	PR c++/93314
	* g++.dg/parse/uneval1.C: New test.