Inline & delete Ty::new_unit, since it's just a field access

compiler/rustc_mir_build/src/build/mod.rs

@@ -997,7 +997,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         match self.unit_temp {
             Some(tmp) => tmp,
             None => {
-                let ty = Ty::new_unit(self.tcx);
+                let ty = self.tcx.types.unit;
                 let fn_span = self.fn_span;
                 let tmp = self.temp(ty, fn_span);
                 self.unit_temp = Some(tmp);