String buffers, part 2d: basic string buffer methods.

Sponsored by fmad.io.

src/lj_errmsg.h

@@ -67,6 +67,7 @@ ERRDEF(PROTMT,	"cannot change a protected metatable")
 ERRDEF(UNPACK,	"too many results to unpack")
 ERRDEF(RDRSTR,	"reader function must return a string")
 ERRDEF(PRTOSTR,	LUA_QL("tostring") " must return a string to " LUA_QL("print"))
+ERRDEF(NUMRNG,	"number out of range")
 ERRDEF(IDXRNG,	"index out of range")
 ERRDEF(BASERNG,	"base out of range")
 ERRDEF(LVLRNG,	"level out of range")