[part 2] Make classes and structures in modules fast-allocated.

Source/modules/webmidi/MIDIAccessInitializer.h

Index: Source/modules/webmidi/MIDIAccessInitializer.h
diff --git a/Source/modules/webmidi/MIDIAccessInitializer.h b/Source/modules/webmidi/MIDIAccessInitializer.h
index 943ad4d0dc652b59f025bc5097c0d0b8965fc96b..e1fb8bd9ce7b4c7349e93110b68621bebe2022a5 100644
--- a/Source/modules/webmidi/MIDIAccessInitializer.h
+++ b/Source/modules/webmidi/MIDIAccessInitializer.h
@@ -22,6 +22,7 @@ class ScriptState;
 class MODULES_EXPORT MIDIAccessInitializer : public ScriptPromiseResolver, public MIDIAccessorClient {
 public:
     struct PortDescriptor {
+        ALLOW_ONLY_INLINE_ALLOCATION();
         String id;
         String manufacturer;
         String name;