jit: fix assertion in GDBJITRegistrationListener

[oltolm]

This fixes the assertion Second attempt to perform debug registration. which happens in GDBJITRegistrationListener. It happens on Linux if compiled in debug mode.

auto cache = ObjectCache::load(path);

This variable contains the code. A reference to it is added to the JIT compiler and then it is destroyed at the end of the function jit_compiler::add and the JIT compiler now has a reference to destroyed code.

I changed it to pass the ownership of the code to the JIT compiler.

[oltolm]

@Nekotekina ping

[oltolm]

Thank you. There is something I don't understand. If my analysis was correct and the JIT compiler used a reference to destroyed code, how did it even work and why did I only get the assertion on Linux and not on Windows?