A Go binary may only have 1 executable memory region if it has been
linked using internal linking. This change means that the test will
be skipped if this is the case, rather than fail.

Fixes #17852.

Change-Id: I59459a0f90ae8963aeb9908e5cb9fb64d7d0e0f4
Reviewed-on: https://go-review.googlesource.com/32920
Run-TryBot: Michael Munday <munday@ca.ibm.com>
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>