[AA] cfl-anders-aa with field sensitivity

Summary:
There was some unfinished work started for offset tracking in CFLGraph by the author of implementation of Andersen algorithm. This work was completed and support for field sensitivity was added to the core of Andersen algorithm.

The performance results seem promising.

SPEC2006 int_base score was increased by 1.1 % (I  compared clang 6.0 with clang 6.0 with this patch). The avergae compile time was increased by +- 1 % according my measures with small and medium C/C++ projects (I did not tested it on the large projects with milions of lines of code)

Reviewers: chandlerc, george.burgess.iv, rja

Reviewed By: rja

Subscribers: rja, llvm-commits

Differential Revision: https://reviews.llvm.org/D46282

llvm-svn: 332657