Explicitly pass in timing functions in mock clock integration specs

- This way we can make sure that clear stack always works no matter
  how long the suite in the spec is

[fixes #153518103]

src/core/util.js

@@ -112,7 +112,7 @@ getJasmineRequireObj().util = function(j$) {
     return false;
   }
 
-  function errorWithStack() {
+  util.errorWithStack = function errorWithStack () {
     // Don't throw and catch if we don't have to, because it makes it harder
     // for users to debug their code with exception breakpoints.
     var error = new Error();
@@ -127,10 +127,10 @@ getJasmineRequireObj().util = function(j$) {
     } catch (e) {
       return e;
     }
-  }
+  };
 
   function callerFile() {
-    var trace = new j$.StackTrace(errorWithStack());
+    var trace = new j$.StackTrace(util.errorWithStack());
     return trace.frames[2].file;
   }