Implement support for the InterruptibleFFI extension.
Merge branch 'master' of github.com:haskell-suite/haskell-src-exts

Conflicts:
	src/Language/Haskell/Exts/Annotated/ExactPrint.hs
	src/Language/Haskell/Exts/Annotated/Simplify.hs
	src/Language/Haskell/Exts/Extension.hs