Fix diagnostics where _Atomic can't be applied

adb290d added a new case to
err_atomic_specifier_bad_type.  The diagnostic has two %select's
controlled by the same argument, but only the first was updated to have
the new case.  Add the extra case for the second %select and add a
test case that exercises the last case.

Author: Weverything

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -5946,7 +5946,7 @@ def err_func_def_incomplete_result : Error<
 def err_atomic_specifier_bad_type : Error<
   "_Atomic cannot be applied to "
   "%select{incomplete |array |function |reference |atomic |qualified |sizeless |}0type "
-  "%1 %select{||||||which is not trivially copyable}0">;
+  "%1 %select{|||||||which is not trivially copyable}0">;
 
 // Expressions.
 def select_unary_expr_or_type_trait_kind : TextSubstitution<

clang/test/SemaCXX/atomic-type.cpp

@@ -103,3 +103,11 @@ namespace copy_init {
 bool PR21836(_Atomic(int) *x) { // expected-warning {{'_Atomic' is a C11 extension}}
     return *x;
 }
+
+namespace non_trivially_copyable {
+  struct S {
+    ~S() {}
+  };
+  _Atomic S s;  // expected-error {{_Atomic cannot be applied to type 'non_trivially_copyable::S' which is not trivially copyable}} \
+                // expected-warning {{'_Atomic' is a C11 extension}}
+}