[Interpreter] Add ClassOf intrinsic.

src/code-stub-assembler.h

Index: src/code-stub-assembler.h
diff --git a/src/code-stub-assembler.h b/src/code-stub-assembler.h
index f29701020791ffe5f67d9099c2236a2b4836d204..a0ca23aa55bedf4c16d180c62fe1f8f343c6b0af 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -153,6 +153,8 @@ class CodeStubAssembler : public compiler::CodeAssembler {
   compiler::Node* LoadMapInstanceSize(compiler::Node* map);
   // Load the inobject properties count of a Map (valid only for JSObjects).
   compiler::Node* LoadMapInobjectProperties(compiler::Node* map);
+  // Load the constructor of a Map (equivalent to Map::GetConstructor()).
+  compiler::Node* LoadMapConstructor(compiler::Node* map);
 
   // Load the hash field of a name.
   compiler::Node* LoadNameHashField(compiler::Node* name);