Fix ScopeInfo::StackSlotIndex to skip over non-locals

src/scopes.cc

Index: src/scopes.cc
diff --git a/src/scopes.cc b/src/scopes.cc
index 64f9584d59dcb5974952981386f3ff9a0ba50cd3..868b714400cb3337e5bd20ba40d6d7c3c6feed09 100644
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -384,7 +384,7 @@ Variable* Scope::LookupLocal(const AstRawString* name) {
   // it's ok to get the Handle<String> here.
   // If we have a serialized scope info, we might find the variable there.
   // There should be no local slot with the given name.
-  DCHECK(scope_info_->StackSlotIndex(*name_handle) < 0 || is_block_scope());
+  DCHECK(scope_info_->StackLocalSlotIndex(*name_handle) < 0);
 
   // Check context slot lookup.
   VariableMode mode;