Pattern synonyms: swap provided/required

This patch swaps the order of provided and required constraints in
a pattern signature, so it now goes

      pattern P :: req => prov => t1 -> ... tn -> res_ty

See the long discussion in Trac #10928.

I think I have found all the places, but I could have missed something
particularly in comments.

There is a Haddock changes; so a submodule update.

1 files changed, 0 insertions, 0 deletions

diff --git a/utils/haddock b/utils/haddock
-Subproject 85b7ed6147c18611b5ef6b606f157086a8203e7
+Subproject 18de4f2f992d3ed41eb83cb073e63304f0271dc