Tests. Improve tclosure8.pp.

Added few assertions.
Little fix. Capturer definition name contains incorrect line and pos.

Cause: we create capturer during parsing of closure of during capturing of variables; current line and pos hence not suits for capturer's name.
Fix: use fileinfo from procedure definition.
Forbid capturing of "var" and "out" parameters.

Problem: "var" parameters are not located on the current stack frame. That is why we can not simply move them into capturer.
Possible wrong solutions:
1. Copy "var" parameters into capturer and copy them back after procedure end. This will broke idea of passing parameters by reference.
2. Copy address into capturer. This will make closures useless. They should not be restricted by time of activation of any function.

Fix: show error message in case of capturing of "var" or "out" parameters.
Test. Forbidden access to "var" and "out" parameters.
Forbid capturing of exception handler's variables.

One very known RAD studio allows, but fails in runtime :p