Stop using `in_band_lifetimes` in compiler crates

[scottmcm]

With more than 50% of the sign-offs needed in #44524 (comment) to remove the feature entirely (EDIT: And now in FCP), I think it's now fine to start updating the compiler code to stop using the nightly feature.

Here are the crates currently using it:

• compiler\rustc_borrowck\src\lib.rs Remove in_band_lifetimes from rustc_borrowck #91879
• compiler\rustc_codegen_llvm\src\lib.rs Remove in_band_lifetimes from rustc_codegen_llvm #91931
• compiler\rustc_codegen_ssa\src\lib.rs Remove in_band_lifetimes from rustc_codegen_ssa #91885
• compiler\rustc_const_eval\src\lib.rs Remove in_band_lifetimes from rustc_const_eval #91887
• compiler\rustc_data_structures\src\lib.rs Stop enabling in_band_lifetimes in rustc_data_structures #91580
• compiler\rustc_hir\src\lib.rs Remove in_band_lifetimes from rustc_hir #91893
• compiler\rustc_incremental\src\lib.rs Remove in_band_lifetimes from rustc_incremental #91894
• compiler\rustc_infer\src\lib.rs Remove in_band_lifetimes from rustc_infer #91878
• compiler\rustc_metadata\src\lib.rs Remove in_band_lifetimes from rustc_metadata #91926
• compiler\rustc_middle\src\lib.rs Remove in_band_lifetimes from rustc_middle #91984
• compiler\rustc_mir_dataflow\src\lib.rs Remove in_band_lifetimes from rustc_mir_dataflow #91922
• compiler\rustc_mir_transform\src\lib.rs Remove in_band_lifetimes from rustc_mir_transform #91638
• compiler\rustc_monomorphize\src\lib.rs Remove in_band_lifetimes for rustc_monomorphize #91895
• compiler\rustc_passes\src\lib.rs Remove in_band_lifetimes for rustc_passes #91896
• compiler\rustc_privacy\src\lib.rs Remove in_band_lifetimes from rustc_privacy #91925
• compiler\rustc_query_impl\src\lib.rs Remove in_band_lifetimes from rustc_query_impl #91923
• compiler\rustc_symbol_mangling\src\lib.rs Remove in_band_lifetimes from rustc_symbol_mangling #91901
• compiler\rustc_trait_selection\src\lib.rs Remove in_band_lifetimes from rustc_trait_selection #91904
• compiler\rustc_traits\src\lib.rs Removed in_band_lifetimes from rustc_traits #91929
• compiler\rustc_typeck\src\lib.rs Remove in_band_lifetimes from rustc_typeck #91882
• library\proc_macro\src\lib.rs Removed in_band_lifetimes from library\proc_macro #91906

I've marked this E-easy as it's very mechanical work. If you're interested in helping out:

• Get your dev environment set up so that you can successfully build the compiler, see https://rustc-dev-guide.rust-lang.org/
• Post the crate you'll tackle, to avoid duplicate work. (I suggest picking ~randomly, not going in order.)
• Delete the #![feature(in_band_lifetimes)] line from the lib.rs file
• Look at the compiler errors, and either
  • See that the undeclared lifetime is single-use, and thus replace it with '_, or
  • If it's used multiple times, declare it at the appropriate scope.
• Once it compiles again, review the git diff to ensure it has only lifetime annotation changes.
• EDIT: Remember to run x.py fmt and x.py test tidy!
• Send a PR cc'ing this issue, and edit your previous post to include the PR number.

If you'd like to see how these PRs end up looking, here's two that I made earlier:

• Stop enabling in_band_lifetimes in rustc_data_structures #91580
• Remove in_band_lifetimes from rustc_mir_transform #91638

(They're also listed in the checklist above.)

[LegionMammal978]

I've worked on rustc_infer (#91878), rustc_codegen_ssa (#91885), rustc_const_eval (#91887), rustc_mir_dataflow (#91922), rustc_query_impl (#91923), rustc_privacy (#91925), and rustc_codegen_llvm (#91931).

[bugadani]

I can give rustc_borrowck a try (#91879)

[Patrick-Poitras]

I'll try with rustc_typeck. 243 errors fixed! (#91882)