[PATCH] Allow users to specify NULL like macros to be replaced

[Dmitri Gribenko]

  I think the tool should suggest macros to use with this argument.  The developer can review the list and pick the ones that should be converted.  This can be a two-step process: when the tool does not convert a NULL-like macro, it prints a diagnostic about it (once per name).  The developer can run the tool over processed code again.

  Imagine someone running this tool.  What will they specify for this option?  I don't think a developer can immediately recall all NULL-like macros in the codebase.

http://llvm-reviews.chandlerc.com/D574