Revert "[analyzer] Handle zeroing CXXConstructExprs."

Per review from Anna, this really should have been two commits, and besides
it's causing problems on our internal buildbot. Reverting until these have
been worked out.

This reverts r184511 / 98123284826bb4ce422775563ff1a01580ec5766.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184561 91177308-0d34-0410-b5e6-96231b3b80d8