Use optimized code map to cache OSR code.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 7dc96f201970eec90466b79f20fa2823271fe737..3d447ae28040492507a86337c9554d66a949c097 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -8705,8 +8705,20 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_CompileForOnStackReplacement) {
           // Prevent regular recompilation if we queue this for OSR.
           // TODO(yangguo): remove this as soon as OSR becomes one-shot.
           function->ReplaceCode(*unoptimized);
+        } else if (function->IsOptimized() &&
+                   !isolate->optimizing_compiler_thread()->
+                       IsQueuedForOSR(function, pc_offset)) {
+          // Function has already been optimized and no OSR job has been queued.
+          // This means that we have found cached code.
+          result = Handle<Code>(function->code());
+          ast_id = result->OsrAstId();
+          ASSERT(!ast_id.IsNone());
+          ASSERT_EQ(ast_id.ToInt(),
+                    unoptimized->TranslatePcOffsetToAstId(pc_offset).ToInt());
+          // Fall through to the part where we use the OSR code.
+        } else {
+          return NULL;
         }
-        return NULL;
       }
       // Fall through to the end in case of failure.
     } else {