cmd/link: don't run TestDWARF in c-archive mode on Windows
Test fix: in dwarf_test.go don't try to run the TestDWARF testpoint on
windows with c-archive build mode (linker + debug/pe support for that
build mode on Windows is not fully baked it seems).
Fixes #35512.
Change-Id: I1c87ff3d62e5b98e75062b184d762fb5ed937745
Reviewed-on: https://go-review.googlesource.com/c/go/+/206899
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>