[ignition] Fix hole check for dynamic local variables

src/ast/scopes.cc

Index: src/ast/scopes.cc
diff --git a/src/ast/scopes.cc b/src/ast/scopes.cc
index 1cb3af312d19875ed8c58f927173491f990f6767..4407db13e203a7089b524454492f8f7d2e001da4 100644
--- a/src/ast/scopes.cc
+++ b/src/ast/scopes.cc
@@ -1650,6 +1650,10 @@ void Scope::ResolveVariable(ParseInfo* info, VariableProxy* proxy) {
 namespace {
 
 bool AccessNeedsHoleCheck(Variable* var, VariableProxy* proxy, Scope* scope) {
+  if (var->mode() == DYNAMIC_LOCAL) {
+    return AccessNeedsHoleCheck(var->local_if_not_shadowed(), proxy, scope);

[adamk, 2016/12/07 17:37:41]

Can you add a DCHECK here:

DCHECK(!var->binding_needs_init());

And a comment? The comment should say that dynamically-introduced variables
themselves never need a hole check (since they're VAR bindings, either from var
or function declarations), but that the thing they shadow might need a hole
check.

+  }
+
   if (!var->binding_needs_init()) {
     return false;
   }