RFE: support compressed symbol tables in `.gnu_debugdata`

[cuviper]

(from https://github.com/rust-lang/backtrace-rs/issues/410#issuecomment-832871699)

It would be really nice to see support for .gnu_debugdata, which contains compressed symbol tables. For example, the elfutils command eu-readelf --elf-section -s file... can read this.

https://fedoraproject.org/wiki/Features/MiniDebugInfo https://sourceware.org/gdb/onlinedocs/gdb/MiniDebugInfo.html

[philipc]

This will need an LZMA decoder, probably the xz2 crate? Should this be a new cargo feature, or enabled for all linux systems?

[cuviper]

Ah, I suppose that's non-trivial, and probably rules out my hope of getting this into std's own backtracing. But for general use, a new cargo feature sounds reasonable to me.

[workingjubilee]

Adding this as a new feature-flagged item sounds plausible. We have discussed enabling compression for related stuff in std where we have linker/OS support for it, at least.