clippy: resolve projections during internal mutability analysis

Author: GrigorenkoPV

src/tools/clippy/clippy_lints/src/non_copy_const.rs

@@ -215,6 +215,12 @@ impl<'tcx> NonCopyConst<'tcx> {
                 .iter()
                 .zip(tys)
                 .any(|(field, ty)| Self::is_value_unfrozen_raw_inner(cx, *field, ty)),
+            ty::Alias(ty::Projection, _) => match cx.tcx.try_normalize_erasing_regions(cx.typing_env(), ty) {
+                Ok(normalized_ty) if ty != normalized_ty => {
+                    Self::is_value_unfrozen_raw_inner(cx, ty::ValTree::Branch(val), normalized_ty)
+                },
+                _ => false,
+            },
             _ => false,
         }
     }

src/tools/clippy/clippy_utils/src/ty/mod.rs

@@ -1227,6 +1227,10 @@ impl<'tcx> InteriorMut<'tcx> {
                         .find_map(|f| self.interior_mut_ty_chain(cx, f.ty(cx.tcx, args)))
                 }
             },
+            ty::Alias(ty::Projection, _) => match cx.tcx.try_normalize_erasing_regions(cx.typing_env(), ty) {
+                Ok(normalized_ty) if ty != normalized_ty => self.interior_mut_ty_chain(cx, normalized_ty),
+                _ => None,
+            },
             _ => None,
         };