cmd/compile: remove unused arg from gorecover

cmd/compile: remove unused arg from gorecover

We don't need this argument anymore to match up
a recover with its corresponding panic.

Change-Id: I5d3646cdd766259ee9d3d995a2f215f02e17abc6
Reviewed-on: https://go-review.googlesource.com/c/go/+/685555
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>