dashboard: add interim illumos builder

While the work to make illumos a first class GCE guest is completed, use
this interim zone provided by an illumos community member to run illumos
builds.

Updates golang/go#15581

Change-Id: I1784847e5407894d01ce0aadf489b38d7e5c1924
Reviewed-on: https://go-review.googlesource.com/c/build/+/201597
Reviewed-by: Brad Fitzpatrick <[email protected]>
Run-TryBot: Brad Fitzpatrick <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>

Author: jclulow

dashboard/builders.go

@@ -441,6 +441,14 @@ var Hosts = map[string]*HostConfig{
 		env:             []string{"GOROOT_BOOTSTRAP=/usr/local/go-bootstrap"},
 		SSHUsername:     "root",
 	},
+	"host-illumos-amd64-jclulow": &HostConfig{
+		Notes:       "SmartOS [email protected] zone",
+		Owner:       "[email protected]",
+		OwnerGithub: "jclulow",
+		IsReverse:   true,
+		ExpectNum:   1,
+		SSHUsername: "gobuild",
+	},
 	"host-solaris-oracle-amd64-oraclerel": &HostConfig{
 		Notes:       "Oracle Solaris amd64 Release System",
 		Owner:       "", // TODO: find current owner
@@ -2012,6 +2020,11 @@ func init() {
 			"CGO_ENABLED=1",
 		},
 	})
+	addBuilder(BuildConfig{
+		Name:             "illumos-amd64",
+		HostType:         "host-illumos-amd64-jclulow",
+		MinimumGoVersion: types.MajorMinor{1, 13},
+	})
 	addBuilder(BuildConfig{
 		Name:     "solaris-amd64-oraclerel",
 		HostType: "host-solaris-oracle-amd64-oraclerel",