Only create ScopeInfos for scopes that really need one

src/ast/scopes.h

Index: src/ast/scopes.h
diff --git a/src/ast/scopes.h b/src/ast/scopes.h
index 44797525ca5153c7f96c9387ff22e33deba30717..581d34ead815923d90ada8fb69c2486252182515 100644
--- a/src/ast/scopes.h
+++ b/src/ast/scopes.h
@@ -444,8 +444,10 @@ class Scope: public ZoneObject {
     // A lazily parsed scope doesn't contain enough information to create a
     // ScopeInfo from it.
     if (is_lazily_parsed_) return false;
-    return NeedsContext() || is_script_scope() || is_function_scope() ||
-           is_eval_scope() || is_module_scope();
+    // The debugger expects all functions to have scope infos.
+    // TODO(jochen|yangguo): Remove this requirement.
+    if (is_function_scope()) return true;
+    return NeedsContext();
   }
 
   Zone* zone_;