[GHC] #11465: Eliminate check_lifted check in TcValidity

[GHC]

#11465: Eliminate check_lifted check in TcValidity
-------------------------------------+-------------------------------------
        Reporter:  simonpj           |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1807
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"07afe448c3a83d7239054baf9d54681ca19766b0/ghc" 07afe44/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="07afe448c3a83d7239054baf9d54681ca19766b0"
 Remove the check_lifted check in TcValidity

 This patch fixes Trac #11465.  The check_unlifted check really isn't
 necessary, as discussed in Trac #11120 comment:19.

 Removing it made just one test-suite change,
 in indexed-types/should_fail/T9357, by allowing

    type family F (a :: k1) :: k2
    type instance F Int# = Int

 to be accepted.  And indeed that seems entirely reasonable.
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11465#comment:5>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler