[PATCH] Some minor update in PassManager.h

[Dinesh Dwivedi]

Resending with my comments [adding cc to Phab hasn't added my comments 
when I added llvm-commits in cc]


This patch results in reduction of few PassModel classes. I have checked these 
changes with existing test cases.

As per my understanding, runImpl will be statically resolved and inlined and will 
not cause any function call overhead. In case, run methods changes to take more
arguments, though possibility is rare, this will be easy to extend.

Are these changes ok?

http://reviews.llvm.org/D3543