Reland "[debug] Add test for promise finally"

This is a reland of a2ed0514
Original change's description:
> [debug] Add test for promise finally
> 
> As of v8:6536, we no longer have to mark builtins explicitly.
> 
> Also remove test whitelist for promise finally
> builtins.
> 
> Bug: v8:6088, v8:5967
> Change-Id: I7f98dfe7708678653e944ac76ba9938205490b16
> Reviewed-on: https://chromium-review.googlesource.com/654067
> Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47896}

TBR=jgruber@chromium.org

Bug: v8:6088, v8:5967
Change-Id: I25a1820e04596a44769fc8ded80678f3663bbcd5
Reviewed-on: https://chromium-review.googlesource.com/655740Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47906}

test/cctest/test-debug.cc

@@ -6523,17 +6523,12 @@ TEST(BuiltinsExceptionPrediction) {
   v8::HandleScope handle_scope(isolate);
   v8::Context::New(isolate);
 
-  // TODO(gsathya): Fix catch prediction for the following.
-  std::set<int> whitelist(
-      {i::Builtins::kPromiseThenFinally, i::Builtins::kPromiseCatchFinally});
-
   i::Builtins* builtins = CcTest::i_isolate()->builtins();
   bool fail = false;
   for (int i = 0; i < i::Builtins::builtin_count; i++) {
     Code* builtin = builtins->builtin(i);
 
     if (builtin->kind() != Code::BUILTIN) continue;
-    if (whitelist.find(i) != whitelist.end()) continue;
 
     auto prediction = builtin->GetBuiltinCatchPrediction();
     USE(prediction);

test/debugger/debug/es8/promise-finally.js

+// Copyright 2017 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.
+
+// Flags: --harmony-promise-finally
+
+Debug = debug.Debug
+
+var exception = null;
+var step = 0;
+
+function listener(event, exec_state, event_data, data) {
+  if (event != Debug.DebugEvent.Exception) return;
+  try {
+    var line = exec_state.frame(0).sourceLineText();
+    var match = /Exception/.exec(line);
+    assertNotNull(match);
+    step++;
+  } catch (e) {
+    exception = e;
+  }
+}
+
+// Caught throw, events on any exception.
+Debug.setListener(listener);
+Debug.setBreakOnException();
+
+var thenable = {
+  get then() {
+    throw new Error('err');  // Exception
+  }
+};
+
+var caughtException = null;
+
+Promise.resolve()
+  .finally(() => thenable)
+  .catch(e => caughtException = e);
+
+%RunMicrotasks();
+
+Debug.setListener(null);
+Debug.clearBreakOnException();
+assertNull(exception);
+assertNotNull(caughtException);
+assertEquals(1, step);