Introduce LanguageMode, drop StrictMode.

src/accessors.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/compiler.h"
 #include "src/contexts.h"
@@ skipping 1394 matching lines @@
   }
   // If caller is bound, return null. This is compatible with JSC, and
   // allows us to make bound functions use the strict function map
   // and its associated throwing caller and arguments.
   if (caller->shared()->bound()) {
     return MaybeHandle<JSFunction>();
   }
   // Censor if the caller is not a sloppy mode function.
   // Change from ES5, which used to throw, see:
   // https://bugs.ecmascript.org/show_bug.cgi?id=310
-  if (caller->shared()->strict_mode() == STRICT) {
+  if (is_strict(caller->shared()->language_mode())) {
     return MaybeHandle<JSFunction>();
   }
   // Don't return caller from another security context.
   if (!AllowAccessToFunction(isolate->context(), caller)) {
     return MaybeHandle<JSFunction>();
   }
   return Handle<JSFunction>(caller);
 }
 
 
@@ skipping 108 matching lines @@
   info->set_data(Smi::FromInt(index));
   Handle<Object> getter = v8::FromCData(isolate, &ModuleGetExport);
   Handle<Object> setter = v8::FromCData(isolate, &ModuleSetExport);
   info->set_getter(*getter);
   if (!(attributes & ReadOnly)) info->set_setter(*setter);
   return info;
 }
 
 
 } }  // namespace v8::internal