Revert of [compiler] Prepare for partially shipping Ignition.

src/compiler-dispatcher/compiler-dispatcher-job.cc

Index: src/compiler-dispatcher/compiler-dispatcher-job.cc
diff --git a/src/compiler-dispatcher/compiler-dispatcher-job.cc b/src/compiler-dispatcher/compiler-dispatcher-job.cc
index 28ec75ed5a64d307403091c9a4c03c846e3f9c57..34f988718146aa8eaaa36e033c8fba8e71fe4f22 100644
--- a/src/compiler-dispatcher/compiler-dispatcher-job.cc
+++ b/src/compiler-dispatcher/compiler-dispatcher-job.cc
@@ -151,10 +151,11 @@
     parse_info_->set_shared_info(shared_);
 
     {
-      // Create a canonical handle scope for compiling Ignition bytecode. This
-      // is required by the constant array builder to de-duplicate objects
-      // without dereferencing handles.
-      CanonicalHandleScope canonical(isolate_);
+      // Create a canonical handle scope if compiling ignition bytecode. This is
+      // required by the constant array builder to de-duplicate objects without
+      // dereferencing handles.
+      std::unique_ptr<CanonicalHandleScope> canonical;
+      if (FLAG_ignition) canonical.reset(new CanonicalHandleScope(isolate_));
 
       // Do the parsing tasks which need to be done on the main thread. This
       // will also handle parse errors.