Tag stubs that rely on instance types as MEGAMORPHIC.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index bd572c2f26b93e6ab5cb2d9e247529c32ff2b18f..25ab6bce70621d281cfee1cb3748d2d09f6c24cc 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -548,7 +548,12 @@ class ICStub: public PlatformCodeStub {
  public:
   explicit ICStub(Code::Kind kind) : kind_(kind) { }
   virtual int GetCodeKind() { return kind_; }
-  virtual InlineCacheState GetICState() { return MONOMORPHIC; }
+  // Currently all IC stubs do not collect explicit type feedback but rather
+  // check the instance type.
+  // TODO(verwaest): These stubs should collect proper type feedback, and should
+  // not check the instance type explicitly (perhaps unless more than
+  // kMaxPolymorphism maps are recorded).
+  virtual InlineCacheState GetICState() { return MEGAMORPHIC; }
 
   bool Describes(Code* code) {
     return GetMajorKey(code) == MajorKey() && code->stub_info() == MinorKey();