support for utf-(16|32)(be|le)

Reference: /n/sources/patch/applied/file-utf-16
Date: Tue May 23 02:16:30 CES 2006
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/file.c	Tue May 23 02:15:52 2006
+++ /sys/src/cmd/file.c	Tue May 23 02:15:39 2006
@@ -528,6 +528,10 @@
 	070707,		0xFFFF,		"cpio archive\n", OCTET,
 	0x2F7,		0xFFFF,		"tex dvi\n", "application/dvi",
 	0xfaff,		0xfeff,		"mp3 audio\n",	"audio/mpeg",
+	0xfeff0000,	0xffffffff,	"utf-32be\n",	"text/plain charset=utf-32be",
+	0xfffe,		0xffffffff,	"utf-32le\n",	"text/plain charset=utf-32le",
+	0xfeff,		0xffff,		"utf-16be\n",	"text/plain charset=utf-16be",
+	0xfffe,		0xffff,		"utf-16le\n",	"text/plain charset=utf-16le",
 };
 
 int