Allow Turbofan optimization of Ignition generators

src/crankshaft/hydrogen.cc

Index: src/crankshaft/hydrogen.cc
diff --git a/src/crankshaft/hydrogen.cc b/src/crankshaft/hydrogen.cc
index 76d1ef51e2c3f9d666a654a4ab808b8c25f7579b..39728cd13a8e1afbc011fe58e4c16b2c5729f19c 100644
--- a/src/crankshaft/hydrogen.cc
+++ b/src/crankshaft/hydrogen.cc
@@ -158,6 +158,11 @@ HCompilationJob::Status HCompilationJob::CreateGraphImpl() {
     return AbortOptimization(kTooManyParametersLocals);
   }
 
+  if (IsGeneratorFunction(info()->shared_info()->kind())) {
+    // Crankshaft does not support generators.
+    return AbortOptimization(kGenerator);
+  }
+
   if (FLAG_trace_hydrogen) {
     isolate()->GetHTracer()->TraceCompilation(info());
   }