[presubmit] Enable readability/namespace linter checking.

src/regexp/bytecodes-irregexp.h

Index: src/regexp/bytecodes-irregexp.h
diff --git a/src/regexp/bytecodes-irregexp.h b/src/regexp/bytecodes-irregexp.h
index 27691422f3700fe4f665d0b06dba541548888025..d6110a3cb53696fcf3e29cabc103af30a5e34002 100644
--- a/src/regexp/bytecodes-irregexp.h
+++ b/src/regexp/bytecodes-irregexp.h
@@ -76,6 +76,8 @@ BYTECODE_ITERATOR(DECLARE_BYTECODES)
   static const int BC_##name##_LENGTH = length;
 BYTECODE_ITERATOR(DECLARE_BYTECODE_LENGTH)
 #undef DECLARE_BYTECODE_LENGTH
-} }
+
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_REGEXP_BYTECODES_IRREGEXP_H_