cmd/link/internal/ld: skip the windows ASLR test when CGO_ENABLED=0

the test case is still using gcc when CGO is disabled.

Change-Id: I2d255bfaeb92816c8343ab72fd7984b6632d421d
GitHub-Last-Rev: de14748bd54c7db8687263a7c37080ec884d982a
GitHub-Pull-Request: golang/go#46120
Reviewed-on: https://go-review.googlesource.com/c/go/+/319169


Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>