As opposed to the clang-fixit tool described on

http://clang.llvm.org/docs/ClangTools.html, this adds -fixit option to
clang-check. Thus, clang-check can become a general-purpose tool to run
clang capitalizing on the info stored in a compilation database.

Review: http://llvm-reviews.chandlerc.com/D51
llvm-svn: 165110