Skip a GC test known to be flaky:

  https://issues.guix.gnu.org/issue/37425
  https://github.com/golang/go/issues/27636

--- go/src/runtime/gc_test.go	2019-09-16 23:10:18.200680387 +0200
+++ go/src/runtime/gc_test.go	2019-09-16 23:11:50.324360646 +0200
@@ -27,6 +27,9 @@ func TestGcSys(t *testing.T) {
 	if runtime.GOOS == "linux" && runtime.GOARCH == "arm64" {
 		t.Skip("skipping test; GOOS=linux GOARCH=arm64 https://github.com/golang/go/issues/27636")
 	}
+	if runtime.GOOS == "linux" {
+		t.Skip("skipping test; GOOS=linux https://issues.guix.gnu.org/issue/37425")
+	}
 	got := runTestProg(t, "testprog", "GCSys")
 	want := "OK\n"
 	if got != want {
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<div class='path'>path: <a href='/guix/log/?id=2bc5dec18505a47644e940f6ae54ab07c69d29da'>root</a>/<a href='/guix/log/build-aux?id=2bc5dec18505a47644e940f6ae54ab07c69d29da'>build-aux</a>/<a href='/guix/log/build-aux/check-channel-news.scm?id=2bc5dec18505a47644e940f6ae54ab07c69d29da'>check-channel-news.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/build-aux/check-channel-news.scm?id=2bc5dec18505a47644e940f6ae54ab07c69d29da&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-05-22 00:35:23 +0200'>2020-05-22</span></td><td><a href='/guix/commit/build-aux/check-channel-news.scm?id=1ad5209d904d471ded6cf53b4e29b64e963dea3f'>maint: Add "make check-channel-news".</a><span class='msg-avail'>...<span class='msg-tooltip'>* build-aux/check-channel-news.scm: New file.
* Makefile.am (EXTRA_DIST): Add it.
(check-channel-news): New phony rule.
* doc/contributing.texi (Commit Access): Mention "make check-channel-news".
</span></span></td><td>Ludovic Courtès</td></tr>