tweak valtree unwrappers inlining

Author: Lukas Markeffsky

Diff for: compiler/rustc_middle/src/ty/consts/valtree.rs

@@ -42,21 +42,29 @@ pub enum ValTreeKind<'tcx> {
 
 impl<'tcx> ValTreeKind<'tcx> {
     #[inline]
+    #[track_caller]
     pub fn unwrap_leaf(&self) -> ScalarInt {
         match self {
             Self::Leaf(s) => *s,
-            _ => bug!("expected leaf, got {:?}", self),
+            _ => self.unwrap_failed(),
         }
     }
 
     #[inline]
+    #[track_caller]
     pub fn unwrap_branch(&self) -> &[ValTree<'tcx>] {
         match self {
             Self::Branch(branch) => &**branch,
-            _ => bug!("expected branch, got {:?}", self),
+            _ => self.unwrap_failed(),
         }
     }
 
+    #[inline(never)]
+    #[track_caller]
+    fn unwrap_failed(&self) -> ! {
+        bug!("unexpected valtree kind, got {self:?}")
+    }
+
     pub fn try_to_scalar(&self) -> Option<Scalar> {
         self.try_to_scalar_int().map(Scalar::Int)
     }