• niteria's avatar
    Make simplifyInstanceContexts deterministic · b58b0e18
    niteria authored
    simplifyInstanceContexts used cmpType which is nondeterministic
    for canonicalising typeclass constraints in derived instances.
    Following changes make it deterministic as explained by the
    Note [Deterministic simplifyInstanceContexts].
    
    Test Plan: ./validate
    
    Reviewers: simonmar, goldfire, simonpj, austin, bgamari
    
    Reviewed By: simonpj
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D2173
    
    GHC Trac Issues: #4012
    b58b0e18
Unique.hs 13.4 KB