Introduce LanguageMode, drop StrictMode.

src/runtime/runtime-compiler.cc

 // Copyright 2014 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/arguments.h"
 #include "src/compiler.h"
 #include "src/deoptimizer.h"
 #include "src/frames.h"
@@ skipping 376 matching lines @@
       script->set_line_offset(Smi::FromInt(-line_num));
     }
   }
   return *fun;
 }
 
 
 static ObjectPair CompileGlobalEval(Isolate* isolate, Handle<String> source,
                                     Handle<SharedFunctionInfo> outer_info,
                                     Handle<Object> receiver,
-                                    StrictMode strict_mode,
+                                    LanguageMode language_mode,
                                     int scope_position) {
   Handle<Context> context = Handle<Context>(isolate->context());
   Handle<Context> native_context = Handle<Context>(context->native_context());
 
   // Check if native context allows code generation from
   // strings. Throw an exception if it doesn't.
   if (native_context->allow_code_gen_from_strings()->IsFalse() &&
       !CodeGenerationFromStringsAllowed(isolate, native_context)) {
     Handle<Object> error_message =
         native_context->ErrorMessageForCodeGenerationFromStrings();
     Handle<Object> error;
     MaybeHandle<Object> maybe_error = isolate->factory()->NewEvalError(
         "code_gen_from_strings", HandleVector<Object>(&error_message, 1));
     if (maybe_error.ToHandle(&error)) isolate->Throw(*error);
     return MakePair(isolate->heap()->exception(), NULL);
   }
 
   // Deal with a normal eval call with a string argument. Compile it
   // and return the compiled function bound in the local context.
   static const ParseRestriction restriction = NO_PARSE_RESTRICTION;
   Handle<JSFunction> compiled;
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
       isolate, compiled,
-      Compiler::GetFunctionFromEval(source, outer_info, context, strict_mode,
+      Compiler::GetFunctionFromEval(source, outer_info, context, language_mode,
                                     restriction, scope_position),
       MakePair(isolate->heap()->exception(), NULL));
   return MakePair(*compiled, *receiver);
 }
 
 
 RUNTIME_FUNCTION_RETURN_PAIR(Runtime_ResolvePossiblyDirectEval) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 6);
 
   Handle<Object> callee = args.at<Object>(0);
 
   // If "eval" didn't refer to the original GlobalEval, it's not a
   // direct call to eval.
   // (And even if it is, but the first argument isn't a string, just let
   // execution default to an indirect call to eval, which will also return
   // the first argument without doing anything).
   if (*callee != isolate->native_context()->global_eval_fun() ||
       !args[1]->IsString()) {
     return MakePair(*callee, isolate->heap()->undefined_value());
   }
 
   DCHECK(args[4]->IsSmi());
-  DCHECK(args.smi_at(4) == SLOPPY || args.smi_at(4) == STRICT);
-  StrictMode strict_mode = static_cast<StrictMode>(args.smi_at(4));
+  DCHECK(is_valid_language_mode(args.smi_at(4)));
+  LanguageMode language_mode = static_cast<LanguageMode>(args.smi_at(4));
   DCHECK(args[5]->IsSmi());
   Handle<SharedFunctionInfo> outer_info(args.at<JSFunction>(2)->shared(),
                                         isolate);
   return CompileGlobalEval(isolate, args.at<String>(1), outer_info,
-                           args.at<Object>(3), strict_mode, args.smi_at(5));
+                           args.at<Object>(3), language_mode, args.smi_at(5));
 }
 }
 }  // namespace v8::internal