unix: provide linux/loong64 assembly for syscalls
unix: provide linux/loong64 assembly for syscalls

Updates golang/go#46229

Change-Id: I0c0d9224312915fc3b86a0cd4abb344286449909
Reviewed-on: https://go-review.googlesource.com/c/sys/+/399335
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
Auto-Submit: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
Reviewed-by: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>

golang/sys,golang/sys,golang/sys