This commit adds support for combining instance allocators with
ActionScript playerglobal class definitions. This is activated
by defining the metadata `[Ruffle(InstanceAllocator = "true")]`
on the ActionScript class definition.
The implementation of this feature is very similar to native methods:
`build_playerglobal` checks for the metadata described above,
and defines a const `NATIVE_INSTANCE_ALLOCATOR_TABLE` mapping
class ids to function pointers.
To demonstrate this feature, I've converted `Event` to ActionScript
(keeping the existing instance allocator function).
I've also converted `ActivityEvent` and `ContextMenuEvent` to
`ActionScript`, to demonstrate how this simplifies inheritance.
In a future PR, we can convert the remaining events to ActionScript,
and remove the `EventData` enum entirely.
Unfortunately, `flex-sdk`'s `asc.jar` compiler strips out all metadata
when the `-optimize` option is passed. As a result, I forked
`flex-sdk` and disabled this behavior:
https://github.com/ruffle-rs/flex-sdk/releases/tag/ruffle-1.0.0
The modified `asc.jar` (built from the forked repository)
is included in this PR, and replaces the our previous 'asc.jar'
downloaded from the official Flex SDK release.
* Change metadata to `[Ruffle(InstanceAllocator)]`
* Strip out metadata before saving bytecode
bb6f07ee1a