[analyzer] Track if a region can be a subclass in the dynamic type info.

When object is allocated with alloc or init, we assume it cannot be a
subclass (currently used only for bifurcation purposes).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161682 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed