Trying to improve x49gp

[Claudio L.]

Done. I applied all your patches and pushed to my github, including the missing one (24) from May. It all works well now.
I was getting and error with the FORTIFY_SOURCE being redefined, so I removed from the Makefile, I don't know if it can affect other platforms (I only tested on Linux).

I also tested it as a debugger, and it worked much better than previously. Now it's fast and responsive, I can inspect any kind of variables, etc.
The only issue is that stepping over one line sometimes jumps many lines, as in goes overboard. For example I single-stepped one line within a loop, and by the time it stopped it had finished the loop and advanced 5 or 6 lines past the end of the loop. But at least now there's no errors when setting and removing breakpoints, and it actually stops at breakpoints (seems trivial but not always worked before).