Register debuginfo to a debugger in jit mode.

[bjorn3]

Wasmtime contains a lot of code to do this. It would be nice to extract this into a common crate.

[bjorn3]

In 020bcb3 the frame table information is now registered to the unwinder in jit mode.

[bjorn3]

I asked for help on how to implement this on the gdb irc. It seems that gdb expects absolute virtual addresses for sections in the elf file. This is quite helpful as it allows the elf file containing the debuginfo to be created entirely without help from cranelift-jit. It may be necessary to copy the code into the elf file too though and point sh_offset to this copy. Thanks @simark for helping me figure this out!

https://gitlab.com/gnutools/binutils-gdb/-/blob/master/gdb/jit.c#L781-793