Left-to-right arrow application is mirrored (AST differs)

[robx]

Describe the bug

Ormolu formats proc a -> x >- a to proc a -> a -< x, which has a different AST.

To Reproduce

$ cat test.hs
{-# LANGUAGE Arrows #-}

foo x = proc a -> x >- a
$ ormolu test.hs
test.hs
  AST of input and AST of formatted code differ.
    at test.hs:3:19-24
  Please, consider reporting the bug.
$ ormolu --unsafe test.hs
{-# LANGUAGE Arrows #-}

foo x = proc a -> a -< x

Expected behavior
ormolu should not fail.

Probably, it shouldn't reformat the example at all, though I suppose an argument could be made for normalizing the direction. In that case, the ASTs should be considered equivalent.

Environment
current master on macos