This was a funny joke that this was here, but it is fundamentally
incompatible with what we're doing. All those users are running proot
anyway because of how broken running under termux directly is.
Just remove this from here.
Previously: Would keep one clone thread's stack active for teardown
delaying.
With aggressive cloning and teardown, this was unsafe.
Only reap the stack when told it is safe to do so.
Which requires moving LinuxEmulation to its own independent folder as
well. Since both IRLoader and FEXLoader rely on it.
No functional change, just moves the the code around.
Paulo Matos