[PATCH] clang-modernize: Add SubprocessCompilationDatabase

[Edwin Vane]

  The problem is the FixedCompilationDatabase mangles the arguments you pass. FixedCompilationDatabase as a result has some preconditions: the name of the compiler should not be present nor should be the filename to operate on. Check CompilationDatabase.h for a better description. As stated in the patch summary we need a simpler compilation database that simply accepts a full list of args and then provides those same args back upon request.

  I'll fix the comment and add a test for -c -c

http://llvm-reviews.chandlerc.com/D1877