Rollup merge of #80039 - LeSeulArtichaut:rm-tyencoder-tcx, r=matthewjasper

Remove unused `TyEncoder::tcx` required method

Unsure if this is helpful or not...

r? ``@ghost`` cc ``@matthewjasper`` ``@jackh726``

Author: JohnTitor

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -319,10 +319,6 @@ impl<'a, 'tcx> TyEncoder<'tcx> for EncodeContext<'a, 'tcx> {
         self.opaque.position()
     }
 
-    fn tcx(&self) -> TyCtxt<'tcx> {
-        self.tcx
-    }
-
     fn type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize> {
         &mut self.type_shorthands
     }

compiler/rustc_middle/src/ty/codec.rs

@@ -69,7 +69,6 @@ impl OpaqueEncoder for rustc_serialize::opaque::Encoder {
 pub trait TyEncoder<'tcx>: Encoder {
     const CLEAR_CROSS_CRATE: bool;
 
-    fn tcx(&self) -> TyCtxt<'tcx>;
     fn position(&self) -> usize;
     fn type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize>;
     fn predicate_shorthands(&mut self) -> &mut FxHashMap<ty::Predicate<'tcx>, usize>;

compiler/rustc_middle/src/ty/query/on_disk_cache.rs

@@ -1044,9 +1044,6 @@ where
 {
     const CLEAR_CROSS_CRATE: bool = false;
 
-    fn tcx(&self) -> TyCtxt<'tcx> {
-        self.tcx
-    }
     fn position(&self) -> usize {
         self.encoder.encoder_position()
     }