[analyzer] Introduce CXXAllocatorCall to handle placement arg invalidation.

This is NOT full-blown support for operator new, but removes some nasty
duplicated code introduced in r158784.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159608 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed