Rollup merge of #102675 - ouz-a:mir-technical-debt, r=oli-obk

Remove `mir::CastKind::Misc`

As discussed in #97649 `mir::CastKind::Misc` is not clear, this PR addresses that by creating a new enum variant for every valid cast.

r? ````@oli-obk````

3 files changed, 11 insertions, 11 deletions

diff --git a/compiler/rustc_const_eval/src/interpret/cast.rs b/compiler/rustc_const_eval/src/interpret/cast.rs
index cbe98548025..764224fd007 100644
--- a/compiler/rustc_const_eval/src/interpret/cast.rs
+++ b/compiler/rustc_const_eval/src/interpret/cast.rs
@@ -42,8 +42,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let res = self.pointer_from_exposed_address_cast(&src, cast_ty)?;
                 self.write_immediate(res, dest)?;
             }
-
-            Misc => {
+            // FIXME: We shouldn't use `misc_cast` for these but handle them separately.
+            IntToInt | FloatToInt | FloatToFloat | IntToFloat | FnPtrToPtr | PtrToPtr => {
                 let src = self.read_immediate(src)?;
                 let res = self.misc_cast(&src, cast_ty)?;
                 self.write_immediate(res, dest)?;
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
index 5eaddf682c3..80ca412b32a 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
@@ -553,7 +553,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 unimplemented!()
             }
 
-            Rvalue::Cast(CastKind::Misc, _, _) => {}
+            Rvalue::Cast(_, _, _) => {}
 
             Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf, _) => {}
             Rvalue::ShallowInitBox(_, _) => {}
diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs
index 23276e60982..87b7c55bf7f 100644
--- a/compiler/rustc_const_eval/src/transform/validate.rs
+++ b/compiler/rustc_const_eval/src/transform/validate.rs
@@ -557,7 +557,14 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             }
             Rvalue::Cast(kind, operand, target_type) => {
                 match kind {
-                    CastKind::Misc => {
+                    CastKind::DynStar => {
+                        // FIXME(dyn-star): make sure nothing needs to be done here.
+                    }
+                    // Nothing to check here
+                    CastKind::PointerFromExposedAddress
+                    | CastKind::PointerExposeAddress
+                    | CastKind::Pointer(_) => {}
+                    _ => {
                         let op_ty = operand.ty(self.body, self.tcx);
                         if op_ty.is_enum() {
                             self.fail(
@@ -568,13 +575,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                             );
                         }
                     }
-                    CastKind::DynStar => {
-                        // FIXME(dyn-star): make sure nothing needs to be done here.
-                    }
-                    // Nothing to check here
-                    CastKind::PointerFromExposedAddress
-                    | CastKind::PointerExposeAddress
-                    | CastKind::Pointer(_) => {}
                 }
             }
             Rvalue::Repeat(_, _)