dashboard: skip x/review on slow 32-bit builders

x/review is fairly disk-intensive (it shells out to 'git'), and also
mostly for use by Go contributors (a smaller subset of Go users in
general). It frequently times out on two particular 32-bit builders.

I don't think we particularly need the coverage from those two
builders for this repo, so rather than trying to speed up the test or
tweak the scale factors, let's just skip it.

Fixes golang/go#49529
Fixes golang/go#49530

Change-Id: I8da1216ebdf9287ae78d52bb03187b65eb33c9ee
Reviewed-on: https://go-review.googlesource.com/c/build/+/363495
Trust: Bryan C. Mills <[email protected]>
Run-TryBot: Bryan C. Mills <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Carlos Amedee <[email protected]>

Author: Bryan C. Mills

dashboard/builders.go

@@ -1900,9 +1900,17 @@ func init() {
 		numTryTestHelpers: 4,
 	})
 	addBuilder(BuildConfig{
-		Name:              "openbsd-386-68",
-		HostType:          "host-openbsd-386-68",
-		tryBot:            explicitTrySet("sys"),
+		Name:     "openbsd-386-68",
+		HostType: "host-openbsd-386-68",
+		tryBot:   explicitTrySet("sys"),
+		buildsRepo: func(repo, branch, goBranch string) bool {
+			if repo == "review" {
+				// https://golang.org/issue/49529: git seems to be too slow on this
+				// platform.
+				return false
+			}
+			return buildRepoByDefault(repo)
+		},
 		distTestAdjust:    noTestDirAndNoReboot,
 		numTryTestHelpers: 4,
 	})
@@ -1975,8 +1983,16 @@ func init() {
 		distTestAdjust: noTestDirAndNoReboot,
 	})
 	addBuilder(BuildConfig{
-		Name:           "netbsd-arm-bsiegert",
-		HostType:       "host-netbsd-arm-bsiegert",
+		Name:     "netbsd-arm-bsiegert",
+		HostType: "host-netbsd-arm-bsiegert",
+		buildsRepo: func(repo, branch, goBranch string) bool {
+			if repo == "review" {
+				// https://golang.org/issue/49530: This test seems to be too slow even
+				// with a long scale factor.
+				return false
+			}
+			return buildRepoByDefault(repo)
+		},
 		distTestAdjust: noTestDirAndNoReboot,
 		tryBot:         nil,
 		env: []string{