Use a different map to distinguish eval contexts

src/runtime/runtime-scopes.cc

Index: src/runtime/runtime-scopes.cc
diff --git a/src/runtime/runtime-scopes.cc b/src/runtime/runtime-scopes.cc
index f634cc119d80bc1f3bf739985d310a72225d67b9..3708e421451034542991114ecc293783597634f7 100644
--- a/src/runtime/runtime-scopes.cc
+++ b/src/runtime/runtime-scopes.cc
@@ -232,7 +232,7 @@ Object* DeclareEvalHelper(Isolate* isolate, Handle<String> name,
   Handle<Context> context(context_arg->declaration_context(), isolate);
 
   DCHECK(context->IsFunctionContext() || context->IsNativeContext() ||
-         context->IsScriptContext() ||
+         context->IsScriptContext() || context->IsEvalContext() ||
          (context->IsBlockContext() && context->has_extension()));
 
   bool is_function = value->IsJSFunction();
@@ -313,6 +313,8 @@ Object* DeclareEvalHelper(Isolate* isolate, Handle<String> name,
     }
     DCHECK(object->IsJSContextExtensionObject() || object->IsJSGlobalObject());
   } else {
+    // Sloppy eval will never have an extension object, as vars are hoisted out,
+    // and lets are known statically.
     DCHECK(context->IsFunctionContext());
     object =
         isolate->factory()->NewJSObject(isolate->context_extension_function());
@@ -702,19 +704,19 @@ RUNTIME_FUNCTION(Runtime_NewScriptContext) {
   return *result;
 }
 
-
 RUNTIME_FUNCTION(Runtime_NewFunctionContext) {
   HandleScope scope(isolate);
-  DCHECK(args.length() == 1);
+  DCHECK(args.length() == 2);
 
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
+  CONVERT_SMI_ARG_CHECKED(scope_type, 1);
 
   DCHECK(function->context() == isolate->context());
   int length = function->shared()->scope_info()->ContextLength();
-  return *isolate->factory()->NewFunctionContext(length, function);
+  return *isolate->factory()->NewFunctionContext(
+      length, function, static_cast<ScopeType>(scope_type));
 }
 
-
 RUNTIME_FUNCTION(Runtime_PushWithContext) {
   HandleScope scope(isolate);
   DCHECK_EQ(3, args.length());