Revert "[analyzer] Keep track of escaped locals"

It was a step in the right direction but it is not clear how can this
fit into the checker API at this point. The pre-escape happens in the
analyzer core and the checker has no control over it. If the checker
is not interestd in a pre-escape it would need to do additional work
on each escape to check if the escaped symbol is originated from an
"uninteresting" pre-escaped memory region. In order to keep the
checker API simple we abandoned this solution for now.

We will reland this once we have a better answer for what to do on the
checker side.

This reverts commit f3a28202.