Merge: Make the `do catch` great again

This PR removes some of the limitations of the `do catch` :
* Hard-coded limit of 100 jumping environments is gone, the array is now dynamic
* The structure for managing jump environments is now lazy initialized
* Now using gcc's `__thread` specifier so that each thread has it's own jumping stack

Pull-Request: #2612
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>

diff --cc src/compiler/abstract_compiler.nit
Simple merge