[presubmit] Enable readability/namespace linter checking.

src/arm64/lithium-codegen-arm64.h

 // Copyright 2013 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_ARM64_LITHIUM_CODEGEN_ARM64_H_
 #define V8_ARM64_LITHIUM_CODEGEN_ARM64_H_
 
 #include "src/arm64/lithium-arm64.h"
 
 #include "src/arm64/lithium-gap-resolver-arm64.h"
@@ skipping 442 matching lines @@
 
   virtual void Emit(Label* label) const = 0;
   virtual void EmitInverted(Label* label) const = 0;
 
  protected:
   MacroAssembler* masm() const { return codegen_->masm(); }
 
   LCodeGen* codegen_;
 };
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_ARM64_LITHIUM_CODEGEN_ARM64_H_