cmd/coordinator: make linux-amd64-racecompile rebuild std/cmd with -c=128

Updates golang/go#19962

Change-Id: I8b938a39b33d4e6b9b8dc5bc0802da95e889ee46
Reviewed-on: https://go-review.googlesource.com/41613
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

dashboard/builders.go

diff --git a/dashboard/builders.go b/dashboard/builders.go
index e818b36..0fbefbb 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -856,6 +856,8 @@
 		Name:                "linux-amd64-racecompile",
 		HostType:            "host-linux-kubestd",
 		CompileOnly:         true,
+		SkipSnapshot:        true,
+		StopAfterMake:       true,
 		InstallRacePackages: []string{"cmd/compile"},
 		Notes:               "race-enabled cmd/compile",
 	})