add constructor to body in order that it was supplied in - fixes #1877

test/core/fixtures/transformation/es6.classes-loose/constructor-order/actual.js

@@ -0,0 +1,13 @@
+class x {
+  f() {
+    1
+    2
+    3
+  }
+
+  constructor() {
+    4
+    5
+    6
+  }
+}

test/core/fixtures/transformation/es6.classes-loose/constructor-order/expected.js

@@ -0,0 +1,19 @@
+"use strict";
+
+var x = (function () {
+  x.prototype.f = function f() {
+    1;
+    2;
+    3;
+  };
+
+  function x() {
+    4;
+    5;
+    6;
+
+    babelHelpers.classCallCheck(this, x);
+  }
+
+  return x;
+})();