Add option for trimming prefix path

[Morganamilo]

Describe the problem you are trying to solve

Currently there's no easy way to trim the path prefix when compiling.

rustc has --remap-path-prefix but this requires you to know the prefix. This is hard to know when using build systems and you can't expect users to have this set when distributing source.

Describe the solution you'd like

I believe we should copy Go:

The new go build flag -trimpath removes all file system paths from the compiled executable, to improve build reproducibility.

With a trimpath option in cargo.toml. This would pass --remap-path-prefix=$CARGO_MANIFEST_DIR=/ to rustc.

This could also perhaps be enabled by default on release builds.

Notes

[Morganamilo]

I would be interested in implementing this myself. Some guidance would be appreciated on how to get this accepted, if I need to write an RFC, etc.

[Morganamilo]

I've just found #5505, which is basically the problem i'm trying to solve here.

[Eh2406]

I will close for now and guide the conversations to continue in #5505 and #9407.