syscall, internal/syscall/unix: Fix getrandom, clone on sparc64
Since sparc is a valid architecture, the name of
getrandom_linux_sparc.go means that it will be ignored on sparc64,
even though it's whitelisted with a +build line.
On SPARC, clone has a unique return value convention which requires
some inline assembly to convert it to the normal convention.
Reviewed-on: https://go-review.googlesource.com/30873
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@241051 138bc75d-0d04-0410-961f-82ee72b054a4