Auto merge of #115214 - Urgau:rfc-3127-trim-paths, r=compiler-errors

Implement rustc part of RFC 3127 trim-paths

This PR implements (or at least tries to) [RFC 3127 trim-paths](rust-lang/rust#111540), the rustc part. That is `-Zremap-path-scope` with all of it's components/scopes.

`@rustbot` label: +F-trim-paths

Author: bors

src/shims/backtrace.rs

@@ -135,7 +135,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             this.tcx.sess.source_map().lookup_char_pos(BytePos(offset.bytes().try_into().unwrap()));
 
         let name = fn_instance.to_string();
-        let filename = lo.file.name.prefer_remapped().to_string();
+        let filename = lo.file.name.prefer_remapped_unconditionaly().to_string();
 
         Ok((fn_instance, lo, name, filename))
     }