Introduce SynchronizedScope to allow heap access from compiler thread.

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 1c332d1736318fdccd8f8a313545019df7e6469a..12f315c33d1a62ec2262bb8aba276d845ee0c9cf 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -1133,6 +1133,8 @@ const char* Logger::TimerEventScope::v8_recompile_synchronous =
     "V8.RecompileSynchronous";
 const char* Logger::TimerEventScope::v8_recompile_concurrent =
     "V8.RecompileConcurrent";
+const char* Logger::TimerEventScope::v8_recompile_synchronized =
+    "V8.RecompileSynchronized";
 const char* Logger::TimerEventScope::v8_compile_full_code =
     "V8.CompileFullCode";
 const char* Logger::TimerEventScope::v8_execute = "V8.Execute";