Print PASS on pass when running standalone test binaries (#3229)

* Add test.batch flag so standalone tests print PASS on pass
* Add comment; use single-dash flag style to match usage elsewhere
* Don't add test.batch for wasmtime
* Skip test.batch unless emulator name is blank
* Remove test.batch flag; buffer test output and show only on verbose or failure
* Remove FAIL when all tests fail to match go test output

main.go

@@ -235,8 +235,9 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 		flags = append(flags, "-test.benchmem")
 	}
 
+	buf := bytes.Buffer{}
 	passed := false
-	err = buildAndRun(pkgName, config, os.Stdout, flags, nil, 0, func(cmd *exec.Cmd, result builder.BuildResult) error {
+	err = buildAndRun(pkgName, config, &buf, flags, nil, 0, func(cmd *exec.Cmd, result builder.BuildResult) error {
 		if testCompileOnly || outpath != "" {
 			// Write test binary to the specified file name.
 			if outpath == "" {
@@ -308,8 +309,12 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 		importPath := strings.TrimSuffix(result.ImportPath, ".test")
 		passed = err == nil
 		if passed {
+			if testVerbose {
+				buf.WriteTo(stdout)
+			}
 			fmt.Fprintf(stdout, "ok  \t%s\t%.3fs\n", importPath, duration.Seconds())
 		} else {
+			buf.WriteTo(stdout)
 			fmt.Fprintf(stdout, "FAIL\t%s\t%.3fs\n", importPath, duration.Seconds())
 		}
 		if _, ok := err.(*exec.ExitError); ok {
@@ -1657,7 +1662,6 @@ func main() {
 		wg.Wait()
 		close(fail)
 		if _, fail := <-fail; fail {
-			fmt.Println("FAIL")
 			os.Exit(1)
 		}
 	case "monitor":

src/testing/testing.go

@@ -449,9 +449,7 @@ func (m *M) Run() (code int) {
 		fmt.Println("FAIL")
 		m.exitCode = 1
 	} else {
-		if flagVerbose {
-			fmt.Println("PASS")
-		}
+		fmt.Println("PASS")
 		m.exitCode = 0
 	}
 	return