[analyzer] Rely on LLVM Dominators in Clang dominator computation.

(Previously, Clang used it's implementation of dominators.)

The patch is contributed by Guoping Long!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145858 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed