Simplify some redundant names

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -315,7 +315,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
             let mut failed = false;
 
             let elaborated_args = std::iter::zip(*args, &generics.params).map(|(arg, param)| {
-                if let Some(ty::Dynamic(obj, _, ty::DynKind::Dyn)) = arg.as_type().map(Ty::kind) {
+                if let Some(ty::Dynamic(obj, _, ty::Dyn)) = arg.as_type().map(Ty::kind) {
                     let default = tcx.object_lifetime_default(param.def_id);
 
                     let re_static = tcx.lifetimes.re_static;
@@ -339,7 +339,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
 
                     has_dyn = true;
 
-                    Ty::new_dynamic(tcx, obj, implied_region, ty::DynKind::Dyn).into()
+                    Ty::new_dynamic(tcx, obj, implied_region, ty::Dyn).into()
                 } else {
                     arg
                 }

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -2348,11 +2348,11 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             GenericKind::Param(ref p) => format!("the parameter type `{p}`"),
             GenericKind::Placeholder(ref p) => format!("the placeholder type `{p:?}`"),
             GenericKind::Alias(ref p) => match p.kind(self.tcx) {
-                ty::AliasKind::Projection | ty::AliasKind::Inherent => {
+                ty::Projection | ty::Inherent => {
                     format!("the associated type `{p}`")
                 }
-                ty::AliasKind::Weak => format!("the type alias `{p}`"),
-                ty::AliasKind::Opaque => format!("the opaque type `{p}`"),
+                ty::Weak => format!("the type alias `{p}`"),
+                ty::Opaque => format!("the opaque type `{p}`"),
             },
         };
 

compiler/rustc_infer/src/infer/relate/combine.rs

@@ -511,7 +511,7 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
                 ));
             } else {
                 match a_ty.kind() {
-                    &ty::Alias(ty::AliasKind::Projection, data) => {
+                    &ty::Alias(ty::Projection, data) => {
                         // FIXME: This does not handle subtyping correctly, we could
                         // instead create a new inference variable for `a_ty`, emitting
                         // `Projection(a_ty, a_infer)` and `a_infer <: b_ty`.
@@ -523,10 +523,9 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
                         ))
                     }
                     // The old solver only accepts projection predicates for associated types.
-                    ty::Alias(
-                        ty::AliasKind::Inherent | ty::AliasKind::Weak | ty::AliasKind::Opaque,
-                        _,
-                    ) => return Err(TypeError::CyclicTy(a_ty)),
+                    ty::Alias(ty::Inherent | ty::Weak | ty::Opaque, _) => {
+                        return Err(TypeError::CyclicTy(a_ty));
+                    }
                     _ => bug!("generalizated `{a_ty:?} to infer, not an alias"),
                 }
             }

compiler/rustc_lint/src/types.rs

@@ -29,7 +29,6 @@ use rustc_span::{Span, Symbol};
 use rustc_target::abi::{Abi, Size, WrappingRange};
 use rustc_target::abi::{Integer, TagEncoding, Variants};
 use rustc_target::spec::abi::Abi as SpecAbi;
-use rustc_type_ir::DynKind;
 
 use std::iter;
 use std::ops::ControlFlow;
@@ -675,7 +674,7 @@ fn lint_wide_pointer<'tcx>(
         }
         match ty.kind() {
             ty::RawPtr(TypeAndMut { mutbl: _, ty }) => (!ty.is_sized(cx.tcx, cx.param_env))
-                .then(|| (refs, matches!(ty.kind(), ty::Dynamic(_, _, DynKind::Dyn)))),
+                .then(|| (refs, matches!(ty.kind(), ty::Dynamic(_, _, ty::Dyn)))),
             _ => None,
         }
     };

compiler/rustc_middle/src/ty/sty.rs

@@ -1225,7 +1225,7 @@ impl<'tcx> AliasTy<'tcx> {
 
     /// Whether this alias type is an opaque.
     pub fn is_opaque(self, tcx: TyCtxt<'tcx>) -> bool {
-        matches!(self.opt_kind(tcx), Some(ty::AliasKind::Opaque))
+        matches!(self.opt_kind(tcx), Some(ty::Opaque))
     }
 
     /// FIXME: rename `AliasTy` to `AliasTerm` and always handle
@@ -2745,7 +2745,7 @@ impl<'tcx> Ty<'tcx> {
             // Extern types have metadata = ().
             | ty::Foreign(..)
             // `dyn*` has no metadata
-            | ty::Dynamic(_, _, DynKind::DynStar)
+            | ty::Dynamic(_, _, ty::DynStar)
             // If returned by `struct_tail_without_normalization` this is a unit struct
             // without any fields, or not a struct, and therefore is Sized.
             | ty::Adt(..)
@@ -2754,7 +2754,7 @@ impl<'tcx> Ty<'tcx> {
             | ty::Tuple(..) => (tcx.types.unit, false),
 
             ty::Str | ty::Slice(_) => (tcx.types.usize, false),
-            ty::Dynamic(_, _, DynKind::Dyn) => {
+            ty::Dynamic(_, _, ty::Dyn) => {
                 let dyn_metadata = tcx.require_lang_item(LangItem::DynMetadata, None);
                 (tcx.type_of(dyn_metadata).instantiate(tcx, &[tail.into()]), false)
             },

compiler/rustc_smir/src/rustc_smir/convert/ty.rs

@@ -12,12 +12,11 @@ use crate::rustc_smir::{alloc, Stable, Tables};
 impl<'tcx> Stable<'tcx> for ty::AliasKind {
     type T = stable_mir::ty::AliasKind;
     fn stable(&self, _: &mut Tables<'tcx>) -> Self::T {
-        use rustc_middle::ty::AliasKind::*;
         match self {
-            Projection => stable_mir::ty::AliasKind::Projection,
-            Inherent => stable_mir::ty::AliasKind::Inherent,
-            Opaque => stable_mir::ty::AliasKind::Opaque,
-            Weak => stable_mir::ty::AliasKind::Weak,
+            ty::Projection => stable_mir::ty::AliasKind::Projection,
+            ty::Inherent => stable_mir::ty::AliasKind::Inherent,
+            ty::Opaque => stable_mir::ty::AliasKind::Opaque,
+            ty::Weak => stable_mir::ty::AliasKind::Weak,
         }
     }
 }
@@ -34,10 +33,9 @@ impl<'tcx> Stable<'tcx> for ty::DynKind {
     type T = stable_mir::ty::DynKind;
 
     fn stable(&self, _: &mut Tables<'tcx>) -> Self::T {
-        use rustc_middle::ty::DynKind;
         match self {
-            DynKind::Dyn => stable_mir::ty::DynKind::Dyn,
-            DynKind::DynStar => stable_mir::ty::DynKind::DynStar,
+            ty::Dyn => stable_mir::ty::DynKind::Dyn,
+            ty::DynStar => stable_mir::ty::DynKind::DynStar,
         }
     }
 }