dashboard: remove nacl builders from the master branch

CL 190998 broke the nacl-386 builder, but nacl support is being
dropped as of Go 1.14 anyway.

Updates golang/go#30439

Change-Id: If9a7ea1230d4af0a127aeb14005063be4092cf84
Reviewed-on: https://go-review.googlesource.com/c/build/+/192537
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/dashboard/builders.go b/dashboard/builders.go
index e592f07..756c21a 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -1421,7 +1421,6 @@
 	}
 	addMiscCompile("-linuxarm", "^linux-arm")        // 2: arm, arm64
 	addMiscCompile("-darwin", "^darwin")             // 4: 386, amd64 + iOS: armb, arm64
-	addMiscCompile("-nacl", "^nacl")                 // 3: arm, 386, amd64p32
 	addMiscCompile("-mips", "^linux-mips")           // 4: mips, mipsle, mips64, mips64le
 	addMiscCompile("-ppc", "^(linux-ppc64|aix-)")    // 3: linux-ppc64{,le}, aix-ppc64
 	addMiscCompile("-solaris", "^(solaris|illumos)") // 2: both amd64
@@ -1634,17 +1633,23 @@
 		},
 	})
 	addBuilder(BuildConfig{
-		Name:              "nacl-386",
-		HostType:          "host-nacl-kube",
-		buildsRepo:        onlyGo,
+		Name:     "nacl-386",
+		HostType: "host-nacl-kube",
+		buildsRepo: func(repo, branch, goBranch string) bool {
+			// nacl support is removed in Go 1.14.
+			return repo == "go" && !atLeastGo1(goBranch, 14)
+		},
 		MaxAtOnce:         2,
 		numTryTestHelpers: 3,
 		env:               []string{"GOOS=nacl", "GOARCH=386", "GOHOSTOS=linux", "GOHOSTARCH=amd64"},
 	})
 	addBuilder(BuildConfig{
-		Name:              "nacl-amd64p32",
-		HostType:          "host-nacl-kube",
-		buildsRepo:        onlyGo,
+		Name:     "nacl-amd64p32",
+		HostType: "host-nacl-kube",
+		buildsRepo: func(repo, branch, goBranch string) bool {
+			// nacl support is removed in Go 1.14.
+			return repo == "go" && !atLeastGo1(goBranch, 14)
+		},
 		tryBot:            explicitTrySet("go"),
 		MaxAtOnce:         2,
 		numTryTestHelpers: 3,
diff --git a/dashboard/builders_test.go b/dashboard/builders_test.go
index 38a5d01..6a029d9 100644
--- a/dashboard/builders_test.go
+++ b/dashboard/builders_test.go
@@ -95,12 +95,10 @@
 				"misc-compile-solaris",
 				"misc-compile-freebsd",
 				"misc-compile-mips",
-				"misc-compile-nacl",
 				"misc-compile-netbsd",
 				"misc-compile-openbsd",
 				"misc-compile-plan9",
 				"misc-compile-ppc",
-				"nacl-amd64p32",
 				"openbsd-amd64-64",
 				"windows-386-2008",
 				"windows-amd64-2016",
@@ -120,7 +118,6 @@
 				"misc-compile-freebsd",
 				"misc-compile-linuxarm",
 				"misc-compile-mips",
-				"misc-compile-nacl",
 				"misc-compile-netbsd",
 				"misc-compile-openbsd",
 				"misc-compile-other",
@@ -393,9 +390,11 @@
 		{b("android-amd64-emu", "go"), isBuilder},
 		{b("android-386-emu", "go"), isBuilder},
 
-		{b("nacl-386", "go"), onlyPost},
+		{b("nacl-386", "go"), none},
+		{b("nacl-386@go1.13", "go"), onlyPost},
 		{b("nacl-386", "net"), none},
-		{b("nacl-amd64p32", "go"), both},
+		{b("nacl-amd64p32", "go"), none},
+		{b("nacl-amd64p32@go1.13", "go"), both},
 		{b("nacl-amd64p32", "net"), none},
 
 		// Only test tip for js/wasm, and only for some repos: