[isabelle-dev] NEWS: update to Poly/ML 5.7.1

[Makarius]

*** System ***

* Update to current Poly/ML 5.7.1 with slightly improved performance and
PIDE markup for identifier bindings.


This refers to Isabelle/3345d53e7c58.

After heroic efforts by David Matthews over some months, we are back on
a live branch of Poly/ML -- one that performs slightly better in most
situations and much better for sessions in
AFP/thys/Ordinary_Differential_Equations (with x86_64).

The PIDE markup mentioned above has been there since Poly/ML 5.7, but we
could not use that officially so far.


	Makarius