[isabelle-dev] NEWS: support for GHC

[Makarius]

*** System ***

* Support for Glasgow Haskell Compiler via command-line tools "isabelle
ghc_setup", "isabelle ghci", "isabelle ghc", "isabelle ghc_stack".
Existing settings variable ISABELLE_GHC is maintained dynamically
according the state of ISABELLE_STACK_ROOT and ISABELLE_STACK_RESOLVER.


This refers to Isabelle/1722cc56d22e.

The Haskell "stack" looks much more solid than OPAM. It works on Windows
without further ado, using native x86_64-windows personality.


	Makarius