Recognize compiled Lua bytecode.

Reference: /n/sources/patch/applied/file-lua
Date: Thu Jul 19 22:49:17 CES 2012
Signed-off-by: lyndon@orthanc.ca

--- /sys/src/cmd/file.c	Thu Jul 19 22:48:57 2012
+++ /sys/src/cmd/file.c	Thu Jul 19 22:48:54 2012
@@ -802,6 +802,7 @@
 	"\033E\033",	"HP PCL printer data",		3,	OCTET,
 	"\033&",	"HP PCL printer data",		2,	OCTET,
 	"\033%-12345X",	"HPJCL file",		9,	"application/hpjcl",
+	"\033Lua",		"Lua bytecode",		4,	OCTET,
 	"ID3",			"mp3 audio with id3",	3,	"audio/mpeg",
 	"\211PNG",		"PNG image",		4,	"image/png",
 	"P3\n",			"ppm",				3,	"image/ppm",