runtime: save/fetch g register during VDSO on linux/loong64
Like arm64, ppc64 and risv64, on loong64, the G register may be temporarily
broken during a VDSO call. If a signal is received during a VDSO call, an
invalid G may be obtained.
See #34391.
Change-Id: Iaffa8cce4f0ef8ef74225c355ec3c20ed238025f
Reviewed-on: https://go-review.googlesource.com/c/go/+/426355 Reviewed-by: WANG Xuerui <git@xen0n.name>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Run-TryBot: WANG Xuerui <git@xen0n.name>
Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>