save_analysis: fix ice in get_expr_data

src/test/ui/save-analysis/issue-73022.rs

@@ -0,0 +1,13 @@
+// build-pass
+// compile-flags: -Zsave-analysis
+enum Enum2 {
+    Variant8 { _field: bool },
+}
+
+impl Enum2 {
+    fn new_variant8() -> Enum2 {
+        Self::Variant8 { _field: true }
+    }
+}
+
+fn main() {}