./x.py: cranelift source paths not mapped to repo root

[matthiaskrgr]

When ./x.py builds librustdoc for example, all paths are originating from the repo root:
--> src/librustdoc/passes/collect_intra_doc_links.rs:2191:16
This this is not the case for recently added cranelift but I guess it should be..?
--> src/intrinsics/mod.rs:827:14
This shouldn't this be --> compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs:827:14?

[jyn514]

I think this happens because cg_clif is in a different workspace.

[jyn514]

cc rust-lang/rust-analyzer#8937