[commit: ghc] wip/spj-tc-branch3's head updated: More constraint-solver refactoring (42d5eb7)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

Branch 'wip/spj-tc-branch3' now includes:

     1c4a39d Prioritise class-level equality costraints
     1221f81 Don't instantaite when typechecking a pattern synonym
     08ba691 Take account of kinds in promoteTcType
     03b0b8e Test Trac #12174
     853cdae Test Trac #12081
     e26f3b7 Make a panic into an ASSERT
     20e7432 Fix a bug in mk_superclasses_of
     fc72e5d Comments only in TcType
     42d5eb7 More constraint-solver refactoring