Include only stuff you need, part 6: Fix cctest.h.

test/cctest/compiler/test-run-stackcheck.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "src/isolate.h"
 #include "test/cctest/compiler/function-tester.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 TEST(TerminateAtMethodEntry) {
   FunctionTester T("(function(a,b) { return 23; })");
 
   T.CheckCall(T.Val(23));
   T.isolate->stack_guard()->RequestTerminateExecution();
   T.CheckThrows(T.undefined(), T.undefined());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8