dashboard: do not sunset windows 2008

CL 363474 added a 2012 builder, which is good, but it also took a major
step in sunsetting Windows 7 support by removing all 2008 builders from
trybots and for Go 1.18+. This will surely bitrot Windows 7 support and
force us to remove support for it, which isn't okay. Rather than line up
dominoes to force our hand on policy, such huge policy changes with
sweeping ramifications should be properly decided.

So, this commit keeps the 2008 builders in the running, alongside the
2012 ones.

Updates golang/go#47845.
Updates golang/go#49490.

Change-Id: I574f51ea22f638d2f9b09fcd00fdfc3097631771
Reviewed-on: https://go-review.googlesource.com/c/build/+/366656
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Carlos Amedee <carlos@golang.org>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>

Author: zx2c4

dashboard/builders.go

@@ -95,7 +95,7 @@ var slowBotAliases = map[string]string{
 	"solaris-amd64":        "solaris-amd64-oraclerel",
 	"wasm":                 "js-wasm",
 	"windows":              "windows-amd64-2016",
-	"windows-386":          "windows-386-2012",
+	"windows-386":          "windows-386-2008",
 	"windows-amd64":        "windows-amd64-2016",
 	"windows-arm":          "windows-arm-zx2c4",
 	"windows-arm64":        "windows-arm64-10",
@@ -1262,7 +1262,7 @@ func (c *BuildConfig) buildsRepoAtAll(repo, branch, goBranch string) bool {
 
 	// Build dev.boringcrypto branches only on linux/amd64 and windows/386 (see golang.org/issue/26791).
 	if repo == "go" && (branch == "dev.boringcrypto" || strings.HasPrefix(branch, "dev.boringcrypto.")) {
-		if c.Name != "linux-amd64" && c.Name != "windows-386-2012" {
+		if c.Name != "linux-amd64" && c.Name != "windows-386-2012" && c.Name != "windows-386-2008" {
 			return false
 		}
 	}
@@ -2186,6 +2186,7 @@ func init() {
 		Name:           "windows-amd64-2008",
 		HostType:       "host-windows-amd64-2008",
 		distTestAdjust: noTestDirAndNoReboot,
+		buildsRepo:     onlyGo,
 		env: []string{
 			"GOARCH=amd64",
 			"GOHOSTARCH=amd64",
@@ -2195,33 +2196,23 @@ func init() {
 			// up:
 			"GO_TEST_TIMEOUT_SCALE=2",
 		},
-		buildsRepo: func(repo, branch, goBranch string) bool {
-			// This builder bill be used up to Go 1.17.
-			return atMostGo1(goBranch, 17) && onlyGo(repo, branch, goBranch)
-		},
 	})
 	addBuilder(BuildConfig{
-		Name:           "windows-386-2008",
-		HostType:       "host-windows-amd64-2008",
-		distTestAdjust: fasterTrybots,
-		env:            []string{"GOARCH=386", "GOHOSTARCH=386"},
-		tryBot:         defaultTrySet(),
-		buildsRepo: func(repo, branch, goBranch string) bool {
-			// This builder bill be used up to Go 1.17.
-			return atMostGo1(goBranch, 17) && defaultPlusExpBuild(repo, branch, goBranch)
-		},
+		Name:              "windows-386-2008",
+		HostType:          "host-windows-amd64-2008",
+		buildsRepo:        defaultPlusExpBuild,
+		distTestAdjust:    fasterTrybots,
+		env:               []string{"GOARCH=386", "GOHOSTARCH=386"},
+		tryBot:            defaultTrySet(),
 		numTryTestHelpers: 4,
 	})
 	addBuilder(BuildConfig{
-		Name:           "windows-386-2012",
-		HostType:       "host-windows-amd64-2012",
-		distTestAdjust: fasterTrybots,
-		env:            []string{"GOARCH=386", "GOHOSTARCH=386"},
-		tryBot:         defaultTrySet(),
-		buildsRepo: func(repo, branch, goBranch string) bool {
-			// This builder is used by Go 1.18 and forward.
-			return atLeastGo1(goBranch, 18) && defaultPlusExpBuild(repo, branch, goBranch)
-		},
+		Name:              "windows-386-2012",
+		HostType:          "host-windows-amd64-2012",
+		distTestAdjust:    fasterTrybots,
+		buildsRepo:        onlyGo,
+		env:               []string{"GOARCH=386", "GOHOSTARCH=386"},
+		tryBot:            defaultTrySet(),
 		numTryTestHelpers: 4,
 	})
 	addBuilder(BuildConfig{

dashboard/builders_test.go

@@ -103,6 +103,7 @@ func TestTrybots(t *testing.T) {
 				"openbsd-amd64-68",
 				"openbsd-amd64-70",
 				"openbsd-amd64-70-n1",
+				"windows-386-2008",
 				"windows-386-2012",
 				"windows-amd64-2016",
 
@@ -137,6 +138,7 @@ func TestTrybots(t *testing.T) {
 				"openbsd-amd64-68",
 				"openbsd-amd64-70",
 				"openbsd-amd64-70-n1",
+				"windows-386-2008",
 				"windows-386-2012",
 				"windows-amd64-2016",
 
@@ -169,6 +171,7 @@ func TestTrybots(t *testing.T) {
 				"linux-arm64-aws",
 				"openbsd-amd64-68",
 				"windows-386-2008",
+				"windows-386-2012",
 				"windows-amd64-2016",
 
 				"misc-compile-darwinarm64", // Starts with Go 1.16.
@@ -205,6 +208,7 @@ func TestTrybots(t *testing.T) {
 				"linux-arm64-aws",
 				"openbsd-amd64-68",
 				"windows-386-2008",
+				"windows-386-2012",
 				"windows-amd64-2016",
 
 				"misc-compile-freebsd",
@@ -257,7 +261,7 @@ func TestTrybots(t *testing.T) {
 				"openbsd-amd64-68",
 				"openbsd-amd64-70",
 				"openbsd-amd64-70-n1",
-				"windows-386-2012",
+				"windows-386-2008",
 				"windows-amd64-2016",
 			},
 		},
@@ -267,7 +271,7 @@ func TestTrybots(t *testing.T) {
 			want: []string{
 				"linux-amd64",
 				"linux-amd64-race",
-				"windows-386-2012",
+				"windows-386-2008",
 				"windows-amd64-2016",
 			},
 		},
@@ -289,12 +293,12 @@ func TestTrybots(t *testing.T) {
 			}
 			for _, b := range got {
 				if _, ok := m[b]; !ok {
-					t.Errorf("got unexpected %q", b)
+					t.Errorf("got unexpected %q for %s/%s", b, tt.repo, tt.branch)
 				}
 				delete(m, b)
 			}
 			for b := range m {
-				t.Errorf("missing expected %q", b)
+				t.Errorf("missing expected %q for %s/%s", b, tt.repo, tt.branch)
 			}
 		})
 	}
@@ -547,8 +551,7 @@ func TestBuilderConfig(t *testing.T) {
 		{b("linux-amd64", "exp"), both},
 		{b("linux-amd64-race", "exp"), both},
 		{b("linux-amd64-longtest", "exp"), onlyPost},
-		{b("windows-386-2008", "exp"), none},
-		{b("windows-386-2012", "exp"), both},
+		{b("windows-386-2008", "exp"), both},
 		{b("windows-amd64-2016", "exp"), both},
 		{b("darwin-amd64-10_14", "exp"), onlyPost},
 		{b("darwin-amd64-10_15", "exp"), onlyPost},