cmd/cgo/internal/testcarchive: fix nocgo and no-c-archive builds

CL 495918 enabled testcarchive much more widely and added many dynamic
test skips. CL 495855 added TestDeepStack before these dynamic skips
were in. Unfortunately, the two CLs don't logically commute, so when
CL 495918 landed, it broke at least nocgo builders and platforms that
don't support c-archive builds. Fix this by adding the necessary skips
to TestDeepStack.

Change-Id: I3d352f731fe67a01c7b96871fde772db8eb21b5d
Reviewed-on: https://go-review.googlesource.com/c/go/+/496376
Auto-Submit: Austin Clements <austin@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>

src/cmd/cgo/internal/testcarchive/carchive_test.go

@@ -1292,6 +1292,10 @@ func TestPreemption(t *testing.T) {
 // Issue 59294. Test calling Go function from C after using some
 // stack space.
 func TestDeepStack(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+	testenv.MustHaveCGO(t)
+	testenv.MustHaveBuildMode(t, "c-archive")
+
 	t.Parallel()
 
 	if !testWork {