Speed up finding code objects from addresses in asserts. With

the new large pages it takes too long to iterate from the start
of the page to find a code object.
Review URL: http://codereview.chromium.org/7974007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9332 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -844,13 +844,7 @@ void Heap::MarkCompactPrologue() {
 
 
 Object* Heap::FindCodeObject(Address a) {
-  Object* obj = NULL;  // Initialization to please compiler.
-  { MaybeObject* maybe_obj = code_space_->FindObject(a);
-    if (!maybe_obj->ToObject(&obj)) {
-      obj = lo_space_->FindObject(a)->ToObjectUnchecked();
-    }
-  }
-  return obj;
+  return isolate()->pc_to_code_cache()->GcSafeFindCodeForPc(a);
 }