Add tcs; it compiles in my world, but I haven't tried it in Russ's yet.

src/cmd/tcs/plan9.h

@@ -0,0 +1,23 @@
+typedef unsigned short Rune;		/* 16 bits */
+typedef unsigned char uchar;
+#define		Runeerror	0x80	/* decoding error in UTF */
+#define		Runeself	0x80	/* rune and UTF sequences are the same (<) */
+#define		UTFmax		6	/* maximum bytes per rune */
+
+/*
+	plan 9 argument parsing
+*/
+#define	ARGBEGIN	for((argv0? 0: (argv0= *argv)),argv++,argc--;\
+			    argv[0] && argv[0][0]=='-' && argv[0][1];\
+			    argc--, argv++) {\
+				char *_args, *_argt, _argc;\
+				_args = &argv[0][1];\
+				if(_args[0]=='-' && _args[1]==0){\
+					argc--; argv++; break;\
+				}\
+				_argc=0;while(*_args) switch(_argc= *_args++)
+#define	ARGEND		}
+#define	ARGF()		(_argt=_args, _args="",\
+				(*_argt? _argt: argv[1]? (argc--, *++argv): 0))
+#define	ARGC()		_argc
+extern char *argv0;