Introduce LanguageMode, drop StrictMode.

src/runtime/runtime.h

 // 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.
 
 #ifndef V8_RUNTIME_RUNTIME_H_
 #define V8_RUNTIME_RUNTIME_H_
 
 #include "src/allocation.h"
 #include "src/objects.h"
 #include "src/zone.h"
@@ skipping 805 matching lines @@
   // TODO(1240886): Some of the following methods are *not* handle safe, but
   // accept handle arguments. This seems fragile.
 
   // Support getting the characters in a string using [] notation as
   // in Firefox/SpiderMonkey, Safari and Opera.
   MUST_USE_RESULT static MaybeHandle<Object> GetElementOrCharAt(
       Isolate* isolate, Handle<Object> object, uint32_t index);
 
   MUST_USE_RESULT static MaybeHandle<Object> SetObjectProperty(
       Isolate* isolate, Handle<Object> object, Handle<Object> key,
-      Handle<Object> value, StrictMode strict_mode);
+      Handle<Object> value, LanguageMode language_mode);
 
   MUST_USE_RESULT static MaybeHandle<Object> DefineObjectProperty(
       Handle<JSObject> object, Handle<Object> key, Handle<Object> value,
       PropertyAttributes attr);
 
   MUST_USE_RESULT static MaybeHandle<Object> GetObjectProperty(
       Isolate* isolate, Handle<Object> object, Handle<Object> key);
 
   MUST_USE_RESULT static MaybeHandle<Object> GetPrototype(
       Isolate* isolate, Handle<Object> object);
@@ skipping 48 matching lines @@
 std::ostream& operator<<(std::ostream&, Runtime::FunctionId);
 
 //---------------------------------------------------------------------------
 // Constants used by interface to runtime functions.
 
 class AllocateDoubleAlignFlag : public BitField<bool, 0, 1> {};
 class AllocateTargetSpace : public BitField<AllocationSpace, 1, 3> {};
 
 class DeclareGlobalsEvalFlag : public BitField<bool, 0, 1> {};
 class DeclareGlobalsNativeFlag : public BitField<bool, 1, 1> {};
-class DeclareGlobalsStrictMode : public BitField<StrictMode, 2, 1> {};
+STATIC_ASSERT(LANGUAGE_END == 2);
+class DeclareGlobalsLanguageMode : public BitField<LanguageMode, 2, 1> {};
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_RUNTIME_RUNTIME_H_