spinda authored Jul 27, 2015 and Ben Gamari committed Jul 27, 2015

UInfixT is like UInfixE or UInfixP but for types. Template Haskell
splices can use it to punt fixity handling to GHC when constructing
types.

UInfixT is converted in compiler/hsSyn/Convert to a right-biased tree of
HsOpTy, which is already rearranged in compiler/rename/RnTypes to match
operator fixities.

This patch consists of (1) adding UInfixT to the AST, (2) implementing
the conversion and updating relevant comments, (3) updating
pretty-printing and library support, and (4) adding tests.

Test Plan: validate

Reviewers: austin, goldfire, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1088

GHC Trac Issues: #10522