[build] Fix header-hygiene warnings for arm64

test/cctest/test-utils-arm64.cc

Index: test/cctest/test-utils-arm64.cc
diff --git a/test/cctest/test-utils-arm64.cc b/test/cctest/test-utils-arm64.cc
index bd1ff998b976a186a52affaaba734a46605e89ae..938328925e87ff693479249db0dcb2df64f03a69 100644
--- a/test/cctest/test-utils-arm64.cc
+++ b/test/cctest/test-utils-arm64.cc
@@ -32,7 +32,8 @@
 #include "test/cctest/cctest.h"
 #include "test/cctest/test-utils-arm64.h"
 
-using namespace v8::internal;
+namespace v8 {
+namespace internal {
 
 
 #define __ masm->
@@ -423,3 +424,6 @@ void RegisterDump::Dump(MacroAssembler* masm) {
 
   completed_ = true;
 }
+
+}  // namespace internal
+}  // namespace v8