cmd/dist: don't test Examples for js/wasm

Fixes #25913

Change-Id: I4701ec94fa4b07211a8beed85c02ee5aa4fe3eb3
Reviewed-on: https://go-review.googlesource.com/119377
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Richard Musiol <neelance@gmail.com>

src/cmd/dist/test.go

@@ -324,6 +324,8 @@ func (t *tester) registerStdTest(pkg string) {
 			}
 			if t.compileOnly {
 				args = append(args, "-run=^$")
+			} else if goos == "js" && goarch == "wasm" {
+				args = append(args, "-run=^Test") // exclude examples; Issue 25913
 			}
 			args = append(args, stdMatches...)
 			cmd := exec.Command("go", args...)
@@ -1335,6 +1337,9 @@ func (t *tester) runFlag(rx string) string {
 	if t.compileOnly {
 		return "-run=^$"
 	}
+	if rx == "" && goos == "js" && goarch == "wasm" {
+		return "-run=^Test" // exclude examples; Issue 25913
+	}
 	return "-run=" + rx
 }