[PATCH] Introducing initial UseAuto transform

[Sean Silva]

> I could if that's preferred. I was modelling on the dump_ast_matchers.py tool in clang/docs/tools which generates LibASTMatchersReference.html that's committed to source control.

That should really be generated when the docs are generated. I'm
pretty sure the only reason that it is committed to source control is
the lack of a simple mechanism to allow running these kinds of jobs on
the server; it is a lost opportunity to automate and hence I consider
it a "bug".

> Do we already have python scripts that run as part of the build?

I don't know; our "check" targets run lit, which is python. We do run
TableGen, and this isn't really too different. If you have very much
difficulty integrating this into the build system you should file a
build system bug. I know at least that with CMake it's not too
difficult to run external commands as part of a build (the first CMake
tutorial that I learned from covered it).

-- Sean Silva