Summary:
Detect if the file is valid UTF-8, and if this is the case, count code
points instead of just using number of bytes in all (hopefully) places, where
number of columns is needed. In particular, use the new
FormatToken.CodePointCount instead of TokenLength where appropriate.
Changed BreakableToken implementations to respect utf-8 character boundaries
when in utf-8 mode.
Reviewers: klimek, djasper
Reviewed By: djasper
CC: cfe-commits, rsmith, gribozavr
Differential Revision: http://llvm-reviews.chandlerc.com/D918
llvm-svn: 183312
