LLVM 3.5 rebase

[Jens Petersen]

llvm-3.5 seems to break Haskell programs compiled with ghc on ARM badly.

> Perhaps I should just barge ahead with a compat-llvm34?

Adam: this would be very welcome for ghc
(ghc only needs llvm - not any clang bits).

Otherwise currently we can't build any Haskell packages in Rawhide
because compiled programs all fail to run on armv7hl with a runtime error:

schedule: re-entered unsafely.
   Perhaps a 'foreign import unsafe' should be 'safe'?

See for example http://koji.fedoraproject.org/koji/getfile?taskID=8036158&name=build.log&offset=-4000
and http://koji.fedoraproject.org/koji/getfile?taskID=8037090&name=build.log&offset=-4000

I just ran into this today and someone else reported the same to ghc upstream last week.

Jens