fix statement doubling when implicitly returning an export

Author: leafo

moonscript/transform.lua

@@ -462,7 +462,10 @@ Statement = Transformer({
         })
       else
         return build.group({
-          node,
+          {
+            "export",
+            node[2]
+          },
           build.assign({
             names = node[2],
             values = node[3]

moonscript/transform.moon

@@ -263,8 +263,9 @@ Statement = Transformer {
           cls
         }
       else
+        -- pull out vawlues and assign them after the export
         build.group {
-          node
+          { "export", node[2] }
           build.assign {
             names: node[2]
             values: node[3]