implement foldl'

fix-builtins/src/lib.rs

@@ -171,6 +171,10 @@ pub enum PrimOpPhase {
     FindFile,
     Floor,
     FoldlStrict,
+    FoldlStrictEmpty,
+    FoldlStrictCall1,
+    FoldlStrictCall2,
+    FoldlStrictUpdate,
     FromJSON,
     FromTOML,
     FunctionArgs,