c++: non-static member, decltype, {} [PR100205]

This test was fixed by my second patch for PR93314, which distinguishes
between constant-expression and potentially-constant-evaluated contexts in a
way that my first patch did not.

	PR c++/100205
	PR c++/99314

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/decltype-nonstatic1.C: New test.

gcc/testsuite/g++.dg/cpp0x/decltype-nonstatic1.C

+// PR c++/100205
+// { dg-do compile { target c++11 } }
+
+struct coordinate_matrix {
+  using index_t = unsigned;
+  struct convert_to_matrix_coordinate {
+    index_t column_id;
+  };
+  index_t column_id;
+
+  // does not work
+  using value_type2 = decltype(convert_to_matrix_coordinate{column_id});
+
+  // does work
+  using value_type5 = decltype(column_id);
+};