Better block comment formatting.
Summary:
1. When splitting one-line block comment, use indentation and *s.
2. Remove trailing whitespace from all lines of a comment, not only the ones being splitted.
3. Add backslashes for all lines if a comment is used insed a preprocessor directive.
Reviewers: djasper
Reviewed By: djasper
CC: cfe-commits, klimek
Differential Revision: http://llvm-reviews.chandlerc.com/D557
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177635
91177308-0d34-0410-b5e6-
96231b3b80d8