Custom fixities for local bindings

[qsctr]

Declaring custom fixities for locally defined operators does not work and it behaves as if you did not specify the fixity at all. From #1371:

I think the problem might with the fixity of operators that are not defined at the top level. For example, this seems to be incorrect also:

f = 10 .-. 2 .-. 1
  where
  infixr 5 .-.
  x .-. y = x - y

The result is 7 (i.e. (10 - 2) - 1) but it should be 9 (10 - (2 - 1)).