dashboard: don't build x/exp and x/mobile on the linux-arm-arm5spacemonkey builder

Updates golang/go#11811

Change-Id: I93aa1f062ba976e1758e5f74b25b20411a59819e
Reviewed-on: https://go-review.googlesource.com/c/build/+/208579
Run-TryBot: Tobias Klauser <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>
Reviewed-by: Brad Fitzpatrick <[email protected]>

Author: tklauser

dashboard/builders.go

@@ -1749,7 +1749,7 @@ func init() {
 			"GO_TEST_TIMEOUT_SCALE=4", // arm is normally 2; double that.
 		},
 		buildsRepo: func(repo, branch, goBranch string) bool {
-			return branch == "master" && goBranch == "master"
+			return branch == "master" && goBranch == "master" && defaultBuildsRepoPolicy(repo, branch, goBranch)
 		},
 		shouldRunDistTest: func(distTest string, isTry bool) bool {
 			if strings.Contains(distTest, "vendor/github.com/google/pprof") {

dashboard/builders_test.go

@@ -307,6 +307,8 @@ func TestBuilderConfig(t *testing.T) {
 		{b("linux-386-387", "crypto"), onlyPost},
 		{b("[email protected]", "net"), none},
 		{b("[email protected]", "net"), none},
+		{b("linux-arm-arm5spacemonkey", "exp"), none},
+		{b("linux-arm-arm5spacemonkey", "mobile"), none},
 
 		// The mobile repo requires Go 1.13+.
 		{b("android-amd64-emu", "go"), both},