Add a class that is useful for hacking around linking problem due to

pass implementations not being linked in when they are used if the
implementation is in a .a file.

  - Fighting with linking problem due to removing the ::ID elements.  Now the
    implementation .cpp files for analyses are not being included into gccas
    and friends because it is linking to the .a file and there is no explicit
    symbol reference to bring in the .o file.  The new IncludeFile hack is the
    result.

llvm-svn: 3434