cmd/buildlet: add linux-loong64 targets

Fixes golang/go#72869.

Change-Id: I1d674651d29ac39e7d6249eae35a55bd5d0a9744
Reviewed-on: https://go-review.googlesource.com/c/build/+/657995
Auto-Submit: Dmitri Shuralyov <[email protected]>
Reviewed-by: Carlos Amedee <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: dmitshur

Diff for: cmd/buildlet/Makefile

@@ -30,6 +30,7 @@ ALL=\
 	buildlet.linux-arm-7 \
 	buildlet.linux-arm-arm5 \
 	buildlet.linux-arm64 \
+	buildlet.linux-loong64 \
 	buildlet.linux-mips \
 	buildlet.linux-mips64 \
 	buildlet.linux-mips64le \
@@ -114,6 +115,9 @@ buildlet.plan9-arm: buildlet.plan9-arm-5
 buildlet.%-arm64: $(GOFILES)
 	GOOS=$* GOARCH=arm64 $(BUILD) $@
 
+buildlet.%-loong64: $(GOFILES)
+	GOOS=$* GOARCH=loong64 $(BUILD) $@
+
 buildlet.%-mips: $(GOFILES)
 	GOOS=$* GOARCH=mips $(BUILD) $@