[release-branch.go1.8] net: increase expected time to dial a closed port on all Darwin ports

All current darwin architectures seem to take at least 100ms to dial a closed port,
and that was making the all.bash script fail.

Fixes #22062

Change-Id: Ib79c4b7a5db2373c95ce5d993cdcbee55cc0667f
Reviewed-on: https://go-review.googlesource.com/67350
Reviewed-by: Ian Lance Taylor <[email protected]>
Reviewed-on: https://go-review.googlesource.com/71331
Run-TryBot: Russ Cox <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>

Author: bmerrill42

src/net/dial_test.go

@@ -225,7 +225,7 @@ func dialClosedPort() (actual, expected time.Duration) {
 	// but other platforms should be instantaneous.
 	if runtime.GOOS == "windows" {
 		expected = 1500 * time.Millisecond
-	} else if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+	} else if runtime.GOOS == "darwin" {
 		expected = 150 * time.Millisecond
 	} else {
 		expected = 95 * time.Millisecond