Support: Partially revert r249782 to unbreak clang build

Apparently the iterators in `clang::CFGBlock` have an auto-conversion to
`CFGBlock *`, but the dereference operator gives `const CFGBlock &`.
Until I have a moment to fix that, revert the GenericDomTree chagnes
from r249782.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249783 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed