cmd/go: convert TestGoTestBuildsAnXtestContainingOnly... to the script framework

The name of the test is too long to fit on the first line. It's
TestGoTestBuildsAnXtestContainingOnlyNonRunnableExamples.

Part of converting all tests to script framework to improve
test parallelism.

Updates #36320
Updates #17751

Change-Id: I490748271b10a85cbe1d34f9dbecb86ccf0101a7
Reviewed-on: https://go-review.googlesource.com/c/go/+/214423
Reviewed-by: Jay Conrod <[email protected]>

Author: matloob

src/cmd/go/go_test.go

@@ -1832,13 +1832,6 @@ func TestListTemplateContextFunction(t *testing.T) {
 	}
 }
 
-func TestGoTestBuildsAnXtestContainingOnlyNonRunnableExamples(t *testing.T) {
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.run("test", "-v", "./testdata/norunexample")
-	tg.grepStdout("File with non-runnable example was built.", "file with non-runnable example was not built")
-}
-
 // Test that you cannot use a local import in a package
 // accessed by a non-local import (found in a GOPATH/GOROOT).
 // See golang.org/issue/17475.

src/cmd/go/testdata/norunexample/example_test.go

@@ -0,0 +1,26 @@
+go test -v norunexample
+stdout 'File with non-runnable example was built.'
+
+-- norunexample/example_test.go --
+package pkg_test
+
+import "os"
+
+func init() {
+	os.Stdout.Write([]byte("File with non-runnable example was built.\n"))
+}
+
+func Example_test() {
+	// This test will not be run, it has no "Output:" comment.
+}
+-- norunexample/test_test.go --
+package pkg
+
+import (
+	"os"
+	"testing"
+)
+
+func TestBuilt(t *testing.T) {
+	os.Stdout.Write([]byte("A normal test was executed.\n"))
+}