[debugger] fix function in suspended generator

R=szuend@chromium.org

Fixed: chromium:1075763
Change-Id: I7f67cfb9c643d8f30bec808ccb2a9e1326ad1921
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2170030Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67450}

src/debug/debug-scopes.cc

@@ -773,7 +773,9 @@ bool ScopeIterator::VisitLocals(const Visitor& visitor, Mode mode) const {
     Variable* function_var =
         current_scope_->AsDeclarationScope()->function_var();
     if (function_var != nullptr) {
-      Handle<JSFunction> function = frame_inspector_->GetFunction();
+      Handle<JSFunction> function = frame_inspector_ == nullptr
+                                        ? function_
+                                        : frame_inspector_->GetFunction();
       Handle<String> name = function_var->name();
       if (visitor(name, function)) return true;
     }

test/inspector/runtime/regress-1075763-expected.txt

+Tests Runtime.evaluate returns object with undefined property.
+{
+    id : <messageId>
+    result : {
+        result : {
+            className : f
+            description : f
+            objectId : <objectId>
+            preview : {
+                description : f
+                overflow : false
+                properties : [
+                    [0] : {
+                        name : [[GeneratorStatus]]
+                        type : string
+                        value : suspended
+                    }
+                ]
+                subtype : generator
+                type : object
+            }
+            subtype : generator
+            type : object
+        }
+    }
+}

test/inspector/runtime/regress-1075763.js

+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+let {session, contextGroup, Protocol} = InspectorTest.start(
+    'Tests Runtime.evaluate returns object with undefined property.');
+
+(async function test() {
+  InspectorTest.logMessage(await Protocol.Runtime.evaluate({
+    expression: "(function* f() {  yield f;})()",
+    generatePreview: true
+  }));
+  InspectorTest.completeTest();
+})();