3d7a0d9b08
This replaces a partial set of non-functional functions with a complete set of functions, all of which actually work. This requires us to implement mbsnrtowcs and wcsnrtombs which completes the set of what we need for libc++. The mbsnrtowcs is basically a copy & paste of wcsnrtombs, but I'm going to go straight to looking at using the OpenBSD UTF-8 implementation rather than keep polishing our home-grown turd. (This patch also opportunistically switches us over to upstream btowc, mbrlen, and wctob, since they're all trivially expressed in terms of other functions.) Change-Id: I0f81443840de0f1aa73b96f0b51988976793a323