[Analyzer] Iterator Checker - Part 7: Support for push and pop operations

[Analyzer] Iterator Checker - Part 7: Support for push and pop operations

This patch adds support for the following operations in the iterator checkers: push_back, push_front, emplace_back, emplace_front, pop_back and pop_front. This affects iterator range checks (range is extended after push and emplace and reduced after pop operations) and invalidation checks (according to the standard).

Differential Revision: https://reviews.llvm.org/D32902

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@341793 91177308-0d34-0410-b5e6-96231b3b80d8