cmd/buildlet: add Makefile target for darwin/arm64

This target updates the buildlet binary used by builders that
test the darwin/arm64 port (i.e., darwin-arm64-11_0-toothrot).

Updates golang/go#39782.

Change-Id: I9247c822a7a103bcc016e81664c67b2fbaa32e03
Reviewed-on: https://go-review.googlesource.com/c/build/+/355312
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
diff --git a/cmd/buildlet/Makefile b/cmd/buildlet/Makefile
index 4e56590..f6608e2 100644
--- a/cmd/buildlet/Makefile
+++ b/cmd/buildlet/Makefile
@@ -11,6 +11,7 @@
 compile:
 	GOOS=aix GOARCH=ppc64 go install golang.org/x/build/cmd/buildlet
 	GOOS=darwin GOARCH=amd64 go install golang.org/x/build/cmd/buildlet
+	GOOS=darwin GOARCH=arm64 go install golang.org/x/build/cmd/buildlet
 	GOOS=dragonfly GOARCH=amd64 go install golang.org/x/build/cmd/buildlet
 	GOOS=freebsd GOARCH=arm go install golang.org/x/build/cmd/buildlet
 	GOOS=freebsd GOARCH=amd64 go install golang.org/x/build/cmd/buildlet
@@ -35,7 +36,7 @@
 	GOOS=windows GOARCH=amd64 go install golang.org/x/build/cmd/buildlet
 
 # buildlet.all is compiles & uploads all targets.
-buildlet.all: FORCE buildlet.aix-ppc64 buildlet.darwin-amd64 buildlet.freebsd-amd64 buildlet.linux-amd64 buildlet.netbsd-386 buildlet.netbsd-amd64 buildlet.netbsd-arm buildlet.openbsd-amd64.go1.10 buildlet.openbsd-386.go1.10 buildlet.openbsd-amd64 buildlet.openbsd-386 buildlet.plan9-386 buildlet.windows-amd64 buildlet.windows-arm buildlet.linux-arm buildlet.linux-arm-arm5 buildlet.linux-arm64 buildlet.linux-riscv64 buildlet.linux-mips buildlet.linux-mipsle buildlet.linux-mips64 buildlet.linux-mips64le buildlet.linux-ppc64 buildlet.linux-ppc64le buildlet.linux-s390x buildlet.solaris-amd64 buildlet.illumos-amd64
+buildlet.all: FORCE buildlet.aix-ppc64 buildlet.darwin-amd64 buildlet.darwin-arm64 buildlet.freebsd-amd64 buildlet.linux-amd64 buildlet.netbsd-386 buildlet.netbsd-amd64 buildlet.netbsd-arm buildlet.openbsd-amd64.go1.10 buildlet.openbsd-386.go1.10 buildlet.openbsd-amd64 buildlet.openbsd-386 buildlet.plan9-386 buildlet.windows-amd64 buildlet.windows-arm buildlet.linux-arm buildlet.linux-arm-arm5 buildlet.linux-arm64 buildlet.linux-riscv64 buildlet.linux-mips buildlet.linux-mipsle buildlet.linux-mips64 buildlet.linux-mips64le buildlet.linux-ppc64 buildlet.linux-ppc64le buildlet.linux-s390x buildlet.solaris-amd64 buildlet.illumos-amd64
 	echo "done"
 
 buildlet.aix-ppc64: FORCE
@@ -46,6 +47,10 @@
 	go install golang.org/x/build/cmd/upload
 	upload --verbose --osarch=$@ --file=go:golang.org/x/build/cmd/buildlet --public --cacheable=false go-builder-data/$@
 
+buildlet.darwin-arm64: FORCE
+	go install golang.org/x/build/cmd/upload
+	upload --verbose --osarch=$@ --file=go:golang.org/x/build/cmd/buildlet --public --cacheable=false go-builder-data/$@
+
 buildlet.dragonfly-amd64: FORCE
 	go install golang.org/x/build/cmd/upload
 	upload --verbose --osarch=$@ --file=go:golang.org/x/build/cmd/buildlet --public --cacheable=false go-builder-data/$@