Remove `PatKind::Box`

compiler/rustc_pattern_analysis/src/rustc.rs

@@ -832,7 +832,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
             Struct if pat.ty().is_box() => {
                 // Outside of the `alloc` crate, the only way to create a struct pattern
                 // of type `Box` is to use a `box` pattern via #[feature(box_patterns)].
-                PatKind::Box { subpattern: hoist(&pat.fields[0]) }
+                PatKind::Print(format!("box {}", hoist(&pat.fields[0])))
             }
             Struct | Variant(_) | UnionField => {
                 let enum_info = match *pat.ty().kind() {

compiler/rustc_pattern_analysis/src/rustc/print.rs

@@ -32,10 +32,6 @@ pub(crate) struct Pat<'tcx> {
 
 #[derive(Clone, Debug)]
 pub(crate) enum PatKind<'tcx> {
-    Box {
-        subpattern: Box<Pat<'tcx>>,
-    },
-
     Deref {
         subpattern: Box<Pat<'tcx>>,
     },
@@ -63,7 +59,6 @@ impl<'tcx> fmt::Display for Pat<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.kind {
             PatKind::Never => write!(f, "!"),
-            PatKind::Box { ref subpattern } => write!(f, "box {subpattern}"),
             PatKind::Deref { ref subpattern } => write_ref_like(f, self.ty, subpattern),
             PatKind::Constant { value } => write!(f, "{value}"),
             PatKind::Range(ref range) => write!(f, "{range}"),