cmd/link: disable a DWARF testpoint on Windows pending investigation
Disable a portion of the TestDWARF testpoint for Windows using
c-archive buildmode, pending investigation of the issue at hand, so as
to get the longtest builder unblocked.
Updates #35512.
Change-Id: Ib72d82ceaa674b9a51da220fb8e225231d5c3433
Reviewed-on: https://go-review.googlesource.com/c/go/+/206557
Run-TryBot: Than McIntosh <thanm@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>