Remove in_band_lifetimes from rustc_middle

See #91867

This was mostly straightforward. In several places, I take advantage
of the fact that lifetimes are non-hygenic: a macro declares the
'tcx' lifetime, which is then used in types passed in as macro
arguments.

compiler/rustc_middle/src/traits/mod.rs

@@ -101,7 +101,7 @@ impl<'tcx> fmt::Debug for ObligationCause<'tcx> {
     }
 }
 
-impl Deref for ObligationCause<'tcx> {
+impl<'tcx> Deref for ObligationCause<'tcx> {
     type Target = ObligationCauseData<'tcx>;
 
     #[inline(always)]