[clang][Interp] Fix broken test case again

Instead of asserting that it's wrong, assert the correct
value.

See the discussion in
a8b5994

Author: tbaederr

clang/test/AST/Interp/c.c

@@ -117,13 +117,11 @@ int somefunc(int i) {
 struct ArrayStruct {
   char n[1];
 };
-struct AA {
-  char name2[(int)&((struct ArrayStruct*)0)->n - 1]; // expected-warning {{folded to constant array}} \
-                                                     // pedantic-expected-warning {{folded to constant array}} \
-                                                     // ref-error {{array size is negative}} \
-                                                     // pedantic-ref-error {{array size is negative}}
-};
-_Static_assert(sizeof(struct AA) == 15, ""); // ref-error {{failed}} \
-                                             // ref-note {{ == 15}} \
-                                             // pedantic-ref-error {{failed}} \
-                                             // pedantic-ref-note {{ == 15}}
+char name2[(int)&((struct ArrayStruct*)0)->n]; // expected-warning {{folded to constant array}} \
+                                               // pedantic-expected-warning {{folded to constant array}} \
+                                               // ref-warning {{folded to constant array}} \
+                                               // pedantic-ref-warning {{folded to constant array}}
+_Static_assert(sizeof(name2) == 0, ""); // expected-error {{failed}} \
+                                        // expected-note {{evaluates to}} \
+                                        // pedantic-expected-error {{failed}} \
+                                        // pedantic-expected-note {{evaluates to}}