[Python-Dev] PyRun_ with file name

["Martin v. Löwis"]

There is a constant issue of mixing CRTs on Windows. Patch 1003535
proposes to work around them by adding yet another PyRun_ function.
I'm in favour, except that:
- it should be called PyRun_Filename
- it should have the maximum current parameter set, i.e. including
   CompilerFlags*

I'm doubtful as to whether specifying an opening mode is necessary.

What do you think?

Martin