unix: add generate component files support for linux/loong64

Updates golang/go#46229

Change-Id: If0ee99997360608d7ba218880a1ef180ca6db551
Reviewed-on: https://go-review.googlesource.com/c/sys/+/399336
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>

unix/linux/mkall.go

@@ -83,6 +83,12 @@ var targets = []target{
 		GNUArch:   "arm-linux-gnueabi",
 		Bits:      32,
 	},
+	{
+		GoArch:    "loong64",
+		LinuxArch: "loongarch",
+		GNUArch:   "loongarch64-linux-gnu",
+		Bits:      64,
+	},
 	{
 		GoArch:    "mips",
 		LinuxArch: "mips",