[commit: ghc] master's head updated: Run simplifier only when the env is clean. (8e8b9ed)

[git at git.haskell.org]

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

Branch 'master' now includes:

     cbcad85 Fix typo in test for #10347.
     2f9809e Slightly better `Coercible` errors.
     e27b267 Perform a validity check on assoc type defaults.
     8e8b9ed Run simplifier only when the env is clean.