Correctly determine ranges for clang-format.

We have been assuming that CharSourceRange::getTokenRange() by itself
expands a range until the end of a token, but in fact it only sets
IsTokenRange to true. Thus, we have so far only considered the first
character of the last token to belong to an unwrapped line. This
did not really manifest in symptoms as all edit integrations
expand ranges to fully lines.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181778 91177308-0d34-0410-b5e6-96231b3b80d8