Bug 1592427: Don't use an AddPtr to access generatorFrames in Debugger::getFrame. r=loganfsmyth

Responsibility for creating entries in Debugger::generatorFrames was moved to
DebuggerFrame::setGenerator, so Debugger::getFrame is only doing lookups now,
and can use the more restricted `Ptr` type for the results of its lookups.

Depends on D56836

Differential Revision: https://phabricator.services.mozilla.com/D56837

--HG--
extra : moz-landing-system : lando

js/src/debugger/Debugger.cpp

@@ -559,14 +559,13 @@ bool Debugger::getFrame(JSContext* cx, const FrameIter& iter,
     // was suspended, popping the stack frame, and later resumed (and we
     // were not stepping, so did not pass through slowPathOnResumeFrame).
     Rooted<AbstractGeneratorObject*> genObj(cx);
-    GeneratorWeakMap::AddPtr gp;
     if (referent.isGeneratorFrame()) {
       {
         AutoRealm ar(cx, referent.callee());
         genObj = GetGeneratorObjectForFrame(cx, referent);
       }
       if (genObj) {
-        gp = generatorFrames.lookupForAdd(genObj);
+        GeneratorWeakMap::Ptr gp = generatorFrames.lookup(genObj);
         if (gp) {
           frame = &gp->value()->as<DebuggerFrame>();
           MOZ_ASSERT(&frame->unwrappedGenerator() == genObj);