cmd/compile: update TestNexting golden file for Delve

This change updates the expected output of the delve debugging session
in the TestNexting internal/ssa test, aligning it with the changes
introduced in CL 147360 and earlier.

Change-Id: I1cc788d02433624a36f4690f24201569d765e5d3
Reviewed-on: https://go-review.googlesource.com/c/147998


Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>