[esnext] Fix various callsites to use is_resumable, not is_generator

src/debug/debug.cc

Index: src/debug/debug.cc
diff --git a/src/debug/debug.cc b/src/debug/debug.cc
index e1f0d489c74e202104f5ba997ef0296638bfdd79..495e162f28194ce34034dcdf5139934728642a9d 100644
--- a/src/debug/debug.cc
+++ b/src/debug/debug.cc
@@ -1329,7 +1329,7 @@ bool Debug::PrepareFunctionForBreakPoints(Handle<SharedFunctionInfo> shared) {
     // smarter here and avoid the heap walk.
     HeapIterator iterator(isolate_->heap());
     HeapObject* obj;
-    bool include_generators = !is_interpreted && shared->is_generator();
+    bool find_resumables = !is_interpreted && shared->is_resumable();
 
     while ((obj = iterator.next())) {
       if (obj->IsJSFunction()) {
@@ -1340,7 +1340,9 @@ bool Debug::PrepareFunctionForBreakPoints(Handle<SharedFunctionInfo> shared) {
         }
         if (is_interpreted) continue;
         if (function->shared() == *shared) functions.Add(handle(function));
-      } else if (include_generators && obj->IsJSGeneratorObject()) {
+      } else if (find_resumables && obj->IsJSGeneratorObject()) {
+        // This case handles async functions as well, as they use generator
+        // objects for in-progress async function execution.
         JSGeneratorObject* generator_obj = JSGeneratorObject::cast(obj);
         if (!generator_obj->is_suspended()) continue;
         JSFunction* function = generator_obj->function();