Skip registration for empty unreachable tails

crates/serc/src/compiler/statement.rs

@@ -3552,6 +3552,9 @@ impl<'source> Compiler<'source> {
             }
             if statement_terminates(statement) {
                 let unreachable = &body[index + 1..];
+                if unreachable.is_empty() {
+                    break;
+                }
                 // A simple keyword call interns its names tuple after visiting all arguments;
                 // name/attribute-only operands retain either folded `__debug__` or that tuple first.
                 if self.output.constants.is_empty()

crates/serc/tests/optimization.rs

@@ -16773,6 +16773,19 @@ assert (sets[0] is sets[1]) == (sys.argv[1] == 'shared')
     }
 }
 
+#[test]
+fn empty_unreachable_tails_preserve_discarded_cache_admissions() {
+    for tail in [
+        "",
+        "                def discarded(default=(\"shared\",)):\n                    return default\n                self.__discarded = discarded\n",
+    ] {
+        let source = format!(
+            "class Outer:\n    class Inner:\n        def method(self, flag):\n            self.__seen = flag\n            if flag:\n                return (\"shared\",)\n{tail}            return (\"shared\",)\n"
+        );
+        assert_matches_cpython(&source, "empty_unreachable_tail.py", &LEVELS);
+    }
+}
+
 #[test]
 fn elided_non_ascii_identifier_preserves_discarded_builders() {
     const PREFIX: &str = "def marker():\n    assert probe.élève\n\n";