[dev.typeparams] runtime: use internal/abi.FuncPCABI0 for sigtramp PC on Plan 9

Same as CL 313230, for Plan 9.

Change-Id: I0e99c095856c4b21b89abdffa4c0699b24ea9428
Reviewed-on: https://go-review.googlesource.com/c/go/+/321330


Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>