Fix elm#1535, order of defs matters!

In some cases, I skipped reversing things back to their original order.
In this case, the original order was important!

There is already a test for this, but I guess I got excited about the
new parse error messages and forgot about this case.

The NonHomogeneousRecords change now matches the previous version:
elm@239af836ec601ce96e57ddc4
a3d8f3a01497e8cf#diff-5d834b6ba7fbbd59d5a79fcc66792e32

src/Parse/Expression.hs

@@ -489,19 +489,19 @@ let_ start =
 
 
 letHelp :: R.Position -> Int -> [Src.RawDef] -> R.Position -> SPos -> ExprParser
-letHelp start oldIndent defs end pos =
+letHelp start oldIndent revDefs end pos =
   oneOf
     [ do  checkAligned pos
           (def, newEnd, newPos) <- definition
-          letHelp start oldIndent (def:defs) newEnd newPos
+          letHelp start oldIndent (def:revDefs) newEnd newPos
 
     , do  setIndent oldIndent
           checkSpace pos
           keyword "in"
           popContext ()
           spaces
           (body, newEnd, newPos) <- expression
-          let letExpr = A.at start end (Src.Let defs body)
+          let letExpr = A.at start end (Src.Let (reverse revDefs) body)
           return ( letExpr, newEnd, newPos )
     ]
 

tests/test-files/good-expected-js/Records/NonHomogeneousRecords.elm.js

@@ -1,6 +1,6 @@
 var _elm_lang$core$Main$bindFields = function (thing) {
-	var x = thing.x;
 	var y = thing.y;
+	var x = thing.x;
 	return thing;
 };
 var _elm_lang$core$Main$Thing = F2(

tests/test-files/good-expected-js/Soundness/IdAnnotated.elm.js

@@ -0,0 +1,6 @@
+var _elm_lang$core$Main$myId = function () {
+	var id = function (x) {
+		return x;
+	};
+	return id;
+}();