Deprecated @:enum, @:extern, @:final

[zommerfelds]

I recently upgraded to Haxe 4.3.1 and noticed deprecation warnings like:

\h3d/scene/Object.hx:392: characters 2-9 : Warning : (WDeprecated) `@:final` is deprecated in favor of `final`
\h3d/scene/Object.hx:623: characters 2-9 : Warning : (WDeprecated) `@:final` is deprecated in favor of `final`
\h3d/shader/Buffers.hx:3: characters 1-7 : Warning : (WDeprecated) `@:enum abstract` is deprecated in favor of `enum abstract`
\hxd/fmt/hmd/Data.hx:3: characters 1-7 : Warning : (WDeprecated) `@:enum abstract` is deprecated in favor of `enum abstract`
\hxd/impl/Allocator.hx:3: characters 1-7 : Warning : (WDeprecated) `@:enum abstract` is deprecated in favor of `enum abstract`
\h2d/Font.hx:110: characters 1-7 : Warning : (WDeprecated) `@:enum abstract` is deprecated in favor of `enum abstract`

I started preparing a PR to replace those, but then realized that maybe you want to keep compatibility for Haxe 3.

What do you think, is it an option to remove support for Haxe 3 in the next version? Happy to prepare a PR.

[ncannasse]

It's fine for me to upgrade to Haxe 4, don't hesitate to submit your PR.