[presubmit] Enable readability/namespace linter checking.

src/mips64/simulator-mips64.h

Index: src/mips64/simulator-mips64.h
diff --git a/src/mips64/simulator-mips64.h b/src/mips64/simulator-mips64.h
index e45cbd449e4f0c230ecc00d175439864011b5143..68d518ea10ef31527ff21041166c797338900394 100644
--- a/src/mips64/simulator-mips64.h
+++ b/src/mips64/simulator-mips64.h
@@ -84,7 +84,8 @@ class SimulatorStack : public v8::internal::AllStatic {
   static inline void UnregisterCTryCatch() { }
 };
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 // Calculated the stack limit beyond which we will throw stack overflow errors.
 // This macro must be called from a C++ method. It relies on being able to take
@@ -526,7 +527,8 @@ class SimulatorStack : public v8::internal::AllStatic {
   }
 };
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // !defined(USE_SIMULATOR)
 #endif  // V8_MIPS_SIMULATOR_MIPS_H_