Use tyCoVarsOfType for CTyEqCan in shouldSplitWD
authorSimon Peyton Jones <simonpj@microsoft.com>
Fri, 3 Feb 2017 16:15:56 +0000 (16:15 +0000)
committerSimon Peyton Jones <simonpj@microsoft.com>
Fri, 3 Feb 2017 17:47:08 +0000 (17:47 +0000)
commitafa409faffba6c340db9ee20f7fa2634ac4f8cd0
tree2e3b3c8aa4effa53541fc7588d6d3f0dc7bc0b3b
parentc2becee48aa73795cbf04905f3891f543f1c746e
Use tyCoVarsOfType for CTyEqCan in shouldSplitWD

An ASSERT failure in rewritableTyVars made me realise
that there was an outright bug in shouldSplitWD.  See
the long Note [Splitting WD constraints].
compiler/typecheck/TcSMonad.hs