runtime/internal/atomic: add riscv64 operators for And/Or
These primitives will be used by the new And/Or sync/atomic apis.
For #61395
Change-Id: I4062d6317e01afd94d3588f5425237723ab15ade
GitHub-Last-Rev:
c0a8d8f34dc355997fa697d4d8da7d45a00bb3c7
GitHub-Pull-Request: golang/go#63272
Reviewed-on: https://go-review.googlesource.com/c/go/+/531575
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Mark Ryan <markdryan@rivosinc.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>