We used 16-bit variables to store the 'character code' everywhere but
this won't let us represent anything beyond U+FFFF.
This patch changes those variables to a custom type that can be 32 or 16
bits depending on the build, and adjusts numerous internal APIs and
datastructures to match. This includes:
* utf8decode() and friends
* font manipulation, caching, rendering, and generation
* on-screen keyboard
* FAT filesystem (parsing and generating utf16 LFNs)
* WIN32 simulator platform code
Note that this patch doesn't _enable_ >16bit unicode support; a followup
patch will turn that on for appropriate targets.
Appears to work on:
* hosted linux, native, linux simulator in both 16/32-bit modes.
Needs testing on:
* windows and macos simulator (16bit+32bit)
Change-Id: Iba111b27d2433019b6bff937cf1ebd2c4353a0e8
a2c10f6189