[isabelle-dev] jdk-8u172

[Makarius]

With Isabelle/72e1d5da30c6 we are on jdk-8u172. This is a routine
update, nothing particularly interesting.

See also
http://www.oracle.com/technetwork/java/javase/8u172-relnotes-4308893.html

Above Oracle also promises another Java 8 release for 17-Jul-2018. Thus
we can include that for the forthcoming Isabelle2018 (published probably
late August 2018).


	Makarius