The patch that introduces handling iterators implemented as pointers may cause crash in some projects because pointer difference is mistakenly handled as pointer decrement. (Similair case for iterators implemented as class instances are already handled correctly.) This patch fixes this issue.
The second case that causes crash is comparison of an iterator implemented as pointer and a null-pointer. This patch contains a fix for this issue as well.
The third case which causes crash is that the checker mistakenly considers all integers as nonloc::ConcreteInt when handling an increment or decrement of an iterator implemented as pointers. This patch adds a fix for this too.
The last case where crashes were detected is when checking for success of an std::advance() operation. Since the modeling of iterators implemented as pointers is still incomplete this may result in an assertion. This patch replaces the assertion with an early exit and adds a FIXME there.