[dev.link] all: reenable cgo internal linking tests

Cgo internal linking was disabled when switching to new object
files. Reeanble the tests, as they get supported.

Change-Id: I11d2ac8785cce73f3a42f6935c10d9f067bc90a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/204520Reviewed-by: Than McIntosh <thanm@google.com>

src/cmd/dist/test.go

@@ -904,9 +904,6 @@ func (t *tester) extLink() bool {
 }
 
 func (t *tester) internalLink() bool {
-	if true { // appease vet...
-		return false // TODO: newobj
-	}
 	if gohostos == "dragonfly" {
 		// linkmode=internal fails on dragonfly since errno is a TLS relocation.
 		return false

src/cmd/nm/nm_cgo_test.go

@@ -37,7 +37,7 @@ func canInternalLink() bool {
 }
 
 func TestInternalLinkerCgoExec(t *testing.T) {
-	if !canInternalLink() || true { // TODO: newobj
+	if !canInternalLink() {
 		t.Skip("skipping; internal linking is not supported")
 	}
 	testGoExec(t, true, false)

src/debug/pe/file_cgo_test.go

@@ -23,7 +23,6 @@ func TestDefaultLinkerDWARF(t *testing.T) {
 }
 
 func TestInternalLinkerDWARF(t *testing.T) {
-	t.Skip("TODO: newobj")
 	testCgoDWARF(t, linkCgoInternal)
 }