[interpreter] Update ForInPrepare to conditionally use runtime.

src/interpreter/interpreter-assembler.h

Index: src/interpreter/interpreter-assembler.h
diff --git a/src/interpreter/interpreter-assembler.h b/src/interpreter/interpreter-assembler.h
index 1b77b52d885540724f514d4ac14102d22a6db7ed..644e773f1696d01020d9c8a63af55c2a329d67c1 100644
--- a/src/interpreter/interpreter-assembler.h
+++ b/src/interpreter/interpreter-assembler.h
@@ -127,6 +127,15 @@ class InterpreterAssembler : public CodeStubAssembler {
                                compiler::Node* first_arg,
                                compiler::Node* arg_count, int return_size = 1);
 
+  // Check the cache validity for |receiver|. Branch to |use_cache| if
+  // valid, otherwise branch to |use_runtime|.
+  void CheckEnumCache(compiler::Node* receiver,
+                      CodeStubAssembler::Label* use_cache,
+                      CodeStubAssembler::Label* use_runtime);
+
+  // Get the enumerable length from |map| and return the result as a Smi.
+  compiler::Node* EnumLength(compiler::Node* map);
+
   // Jump relative to the current bytecode by |jump_offset|.
   compiler::Node* Jump(compiler::Node* jump_offset);