[compiler] Remove dangerous language mode accessors.

src/compiler.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_COMPILER_H_
 #define V8_COMPILER_H_
 
 #include "src/allocation.h"
 #include "src/ast/ast.h"
 #include "src/bailout-reason.h"
@@ skipping 160 matching lines @@
 
   ParseInfo* parse_info() const { return parse_info_; }
 
   // -----------------------------------------------------------
   // TODO(titzer): inline and delete accessors of ParseInfo
   // -----------------------------------------------------------
   Handle<Script> script() const;
   bool is_eval() const;
   bool is_native() const;
   bool is_module() const;
-  LanguageMode language_mode() const;
   FunctionLiteral* literal() const;
   Scope* scope() const;
   Handle<Context> context() const;
   Handle<SharedFunctionInfo> shared_info() const;
   bool has_shared_info() const;
   // -----------------------------------------------------------
 
   Isolate* isolate() const {
     return isolate_;
   }
@@ skipping 428 matching lines @@
   MUST_USE_RESULT Status SetLastStatus(Status status) {
     last_status_ = status;
     return last_status_;
   }
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_H_