Introduce LanguageMode, drop StrictMode.

src/code-stubs-hydrogen.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/bailout-reason.h"
 #include "src/code-stubs.h"
 #include "src/field-index.h"
 #include "src/hydrogen.h"
@@ skipping 1548 matching lines @@
       Add<HConstant>(factory->empty_fixed_array());
   HValue* shared_info = GetParameter(0);
 
   AddIncrementCounter(counters->fast_new_closure_total());
 
   // Create a new closure from the given function info in new space
   HValue* size = Add<HConstant>(JSFunction::kSize);
   HInstruction* js_function =
       Add<HAllocate>(size, HType::JSObject(), NOT_TENURED, JS_FUNCTION_TYPE);
 
-  int map_index = Context::FunctionMapIndex(casted_stub()->strict_mode(),
+  int map_index = Context::FunctionMapIndex(casted_stub()->language_mode(),
                                             casted_stub()->kind());
 
   // Compute the function map in the current native context and set that
   // as the map of the allocated object.
   HInstruction* native_context = BuildGetNativeContext();
   HInstruction* map_slot_value = Add<HLoadNamedField>(
       native_context, nullptr, HObjectAccess::ForContextSlot(map_index));
   Add<HStoreNamedField>(js_function, HObjectAccess::ForMap(), map_slot_value);
 
   // Initialize the rest of the function.
@@ skipping 646 matching lines @@
   // megamorphic case is handled as part of the default stub.
   DCHECK(!FLAG_vector_ics);
 
   // Probe the stub cache.
   Add<HTailCallThroughMegamorphicCache>(receiver, name);
 
   // We never continue.
   return graph()->GetConstant0();
 }
 } }  // namespace v8::internal