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

Remove `mir::CastKind::Misc`

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

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

clippy_utils/src/qualify_min_const_fn.rs

@@ -129,7 +129,12 @@ fn check_rvalue<'tcx>(
         | Rvalue::Use(operand)
         | Rvalue::Cast(
             CastKind::PointerFromExposedAddress
-            | CastKind::Misc
+            | CastKind::IntToInt
+            | CastKind::FloatToInt
+            | CastKind::IntToFloat
+            | CastKind::FloatToFloat
+            | CastKind::FnPtrToPtr
+            | CastKind::PtrToPtr
             | CastKind::Pointer(PointerCast::MutToConstPointer | PointerCast::ArrayToPointer),
             operand,
             _,