Remove unnecessary isolate TLS from compiler jobs

src/optimizing-compiler-thread.cc

Index: src/optimizing-compiler-thread.cc
diff --git a/src/optimizing-compiler-thread.cc b/src/optimizing-compiler-thread.cc
index a5ab106405ac9b29dc469ffebbe5f2072dd953b4..0e5bd1db333bdd1043ad2fc3fe95584ca087ab67 100644
--- a/src/optimizing-compiler-thread.cc
+++ b/src/optimizing-compiler-thread.cc
@@ -25,7 +25,6 @@ class OptimizingCompilerThread::CompileTask : public v8::Task {
  private:
   // v8::Task overrides.
   virtual void Run() OVERRIDE {
-    Isolate::SetIsolateThreadLocals(isolate_, NULL);
     DisallowHeapAllocation no_allocation;
     DisallowHandleAllocation no_handles;
     DisallowHandleDereference no_deref;