Move compiler cctests into v8::internal::compiler namespace.

test/cctest/compiler/test-pipeline.cc

Index: test/cctest/compiler/test-pipeline.cc
diff --git a/test/cctest/compiler/test-pipeline.cc b/test/cctest/compiler/test-pipeline.cc
index 9629e4faca5d23d21d2a871dd565e701657dc066..c00fa6a331ef97bf160833b16173f9edb9f947d0 100644
--- a/test/cctest/compiler/test-pipeline.cc
+++ b/test/cctest/compiler/test-pipeline.cc
@@ -11,8 +11,9 @@
 #include "src/parser.h"
 #include "test/cctest/cctest.h"
 
-using namespace v8::internal;
-using namespace v8::internal::compiler;
+namespace v8 {
+namespace internal {
+namespace compiler {
 
 static void RunPipeline(Zone* zone, const char* source) {
   Handle<JSFunction> function = Handle<JSFunction>::cast(v8::Utils::OpenHandle(
@@ -40,3 +41,7 @@ TEST(PipelineGeneric) {
   FLAG_turbo_types = false;
   RunPipeline(handles.main_zone(), "(function(a,b) { return a + b; })");
 }
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8