Add support for LoongArch64 (#1003)

Makefile

@@ -36,7 +36,8 @@ ALL_LINUX = linux-amd64 \
 	linux-mips64 \
 	linux-mips64le \
 	linux-mips-softfloat \
-	linux-riscv64
+	linux-riscv64 \
+        linux-loong64
 
 ALL_FREEBSD = freebsd-amd64 \
 	freebsd-arm64

udp/udp_linux_64.go

@@ -1,6 +1,6 @@
-//go:build linux && (amd64 || arm64 || ppc64 || ppc64le || mips64 || mips64le || s390x || riscv64) && !android && !e2e_testing
+//go:build linux && (amd64 || arm64 || ppc64 || ppc64le || mips64 || mips64le || s390x || riscv64 || loong64) && !android && !e2e_testing
 // +build linux
-// +build amd64 arm64 ppc64 ppc64le mips64 mips64le s390x riscv64
+// +build amd64 arm64 ppc64 ppc64le mips64 mips64le s390x riscv64 loong64
 // +build !android
 // +build !e2e_testing