misc: log 'ok' from 'go run' tests on success

Otherwise, these tests produce no output, which can make the overall
output of all.bash a bit tricky to decipher.

Updates #30316
Updates #29062

Change-Id: I33b9e070fd28b9f21ece128e9e603a982c08b7cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/208483
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>

misc/cgo/testasan/main.go

@@ -36,14 +36,21 @@ thread(void *p)
 import "C"
 
 import (
+	"fmt"
+	"os"
+	"path/filepath"
 	"time"
 )
 
 func main() {
+	start := time.Now()
+
 	// ensure that we can function normally
 	var v [][]byte
 	for i := 0; i < 1000; i++ {
 		time.Sleep(10 * time.Microsecond)
 		v = append(v, make([]byte, 64<<10))
 	}
+
+	fmt.Printf("ok\t%s\t%s\n", filepath.Base(os.Args[0]), time.Since(start).Round(time.Millisecond))
 }

misc/cgo/testsigfwd/main.go

@@ -25,6 +25,7 @@ static void sigsegv() {
 
 static void segvhandler(int signum) {
 	if (signum == SIGSEGV) {
+		fprintf(stdout, "ok\ttestsigfwd\n");
 		exit(0);  // success
 	}
 }

src/cmd/dist/test.go

@@ -692,7 +692,7 @@ func (t *tester) registerTests() {
 			t.registerTest("testplugin", "../misc/cgo/testplugin", t.goTest(), t.timeout(600), ".")
 		}
 		if gohostos == "linux" && goarch == "amd64" {
-			t.registerTest("testasan", "../misc/cgo/testasan", "go", "run", "main.go")
+			t.registerTest("testasan", "../misc/cgo/testasan", "go", "run", ".")
 		}
 		if mSanSupported(goos, goarch) {
 			t.registerHostTest("testsanitizers/msan", "../misc/cgo/testsanitizers", "misc/cgo/testsanitizers", ".")
@@ -701,7 +701,7 @@ func (t *tester) registerTests() {
 			t.registerHostTest("cgo_errors", "../misc/cgo/errors", "misc/cgo/errors", ".")
 		}
 		if gohostos == "linux" && t.extLink() {
-			t.registerTest("testsigfwd", "../misc/cgo/testsigfwd", "go", "run", "main.go")
+			t.registerTest("testsigfwd", "../misc/cgo/testsigfwd", "go", "run", ".")
 		}
 	}