fix Issue 14432 - move construction for RefCounted

[MartinNowak]

• add RefCounted!T.this(T) which takes an RValue or a copy
  and use move to initialized the refcounted store
• add refCounted to infer T from the argument and disable
  RefCounted's autoInit, also move initializes the store

[JakobOvrum]

You can't use enforce for malloc, use core.exception.onOutOfMemoryError.

See also #3031.

[MartinNowak]

Done

[JakobOvrum]

Why put this in TLS instead of the stack? Could also use typeid(T).init() like destroy does.

[MartinNowak]

Mmh, I just copied the move code. Updated.

[MartinNowak]

Also changed move to use typeid(T).init() instead of an "empty" TLS variable.
This stuff would be way move efficient, if we had destructive move.

[MartinNowak]

Once #3139 is ready, we should specifically handle promoting a Unique!T to a RefCounted!T.

[JakobOvrum]

LGTM

[MartinNowak]

Well then go ahead merge it ;).

[JakobOvrum]

Ideally a third person would look over it, but it's already been 10 days so...

[JakobOvrum]

Auto-merge toggled on

[MartinNowak]

Ideally a third person would look over it

Ideally we'd handle PR within a few days.
I made a best-effort implementation, you did a best-effort review, there is nothing wrong with making mistakes.