Rewrite libpsx thread shutdown path to support musl.

Addresses:

   https://bugzilla.kernel.org/show_bug.cgi?id=208477

Removed the non-wrapping libpsx macro hacks. The API surface as such
becomes a little smaller and I now have confidence that wrapping
pthread_create using the linker options works with Go, gcc and musl
compilers. I feel it is stable enough to call good to delete the
workarounds.

Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
8 files changed