Fuzzbugfix: actually do need eager liveness computation; must uphold invariant that all earlier-in-postorder blocks have full livein sets.

src/bitvec.rs

@@ -177,7 +177,7 @@ impl<'a> std::iter::Iterator for AdaptiveMapIter<'a> {
 
 /// A conceptually infinite-length bitvector that allows bitwise operations and
 /// iteration over set bits efficiently.
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub struct BitVec {
     elems: AdaptiveMap,
 }
@@ -275,6 +275,13 @@ impl Iterator for SetBitsIter {
     }
 }
 
+impl std::fmt::Debug for BitVec {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        let vals = self.iter().collect::<Vec<_>>();
+        write!(f, "{:?}", vals)
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::BitVec;