Separate debug info from .so file

[Mothblocks]

After #119, the release build of librust_g.so is 70 MB as opposed to the previous 10 MB.

This is extremely unideal. There are two ways I see to solve this.

One is that we make release w/ debug info a separate target, then ship both librust_g.so and librust_g_debug_info.so.

Another is that there might be a way to split it into its own file much like the .pdb. There's a few StackOverflow posts about this, something about objcopy? Not sure how doable it is but that would be ideal if it's feasible

[willox]

No need for separate targets. The binaries can be stripped post-build with the strip command line utility.

I'm not sure this really needs to be done on this repo since people can do it themselves, but it's no big deal.

[willox]

It's a little bit of a "standard" to have x.so and x.so.dbg available and to use the debug version when necessary for debugging core dumps.

Both are valid binaries (but the former has been stripped.)

[Mothblocks]

SpaceManiac gave this:

objcopy --only-keep-debug "$INPUT" "$INPUT.dbg"
strip "$INPUT"
objcopy --add-gnu-debuglink="$INPUT.dbg" "$INPUT"

[Mothblocks]

This new change in 1.65.0 could prove useful: https://blog.rust-lang.org/2022/11/03/Rust-1.65.0.html#splitting-linux-debuginfo