[compiler] Consistently use Ignition+TurboFan for lexical variables.

src/ast/ast-numbering.cc

Index: src/ast/ast-numbering.cc
diff --git a/src/ast/ast-numbering.cc b/src/ast/ast-numbering.cc
index f3ba04d571b2b3b6f51bd0bf9d0371d534616fa9..a01f7224ee720839566689f10487a56d7953ccd3 100644
--- a/src/ast/ast-numbering.cc
+++ b/src/ast/ast-numbering.cc
@@ -158,6 +158,9 @@ void AstNumberingVisitor::VisitVariableProxyReference(VariableProxy* node) {
     default:
       break;
   }
+  if (IsLexicalVariableMode(node->var()->mode())) {

[adamk, 2016/12/05 20:47:31]

As noted on the other CL (fixing a perf regression in array.js), it seems like
this check could be narrowed to

  IsLexicalVariableMode() && node->var()->binding_needs_init()

(or maybe you don't even need IsLexicalVariableMode()). That would avoid
disabling crankshaft for the case of named function expressions (which never
need a hole check for the function name var). Thoughts?

[Benedikt Meurer, 2016/12/06 05:10:48]

Ah perfect, thanks a lot Adam for the investigation and the explanation. I was a
bit puzzled that this affected named function expressions. I'll change it to
node->var()->binding_needs_init() only.

+    DisableFullCodegenAndCrankshaft(kReferenceToLetOrConstVariable);
+  }
   node->set_base_id(ReserveIdRange(VariableProxy::num_ids()));
 }