Update Graal

afc5188862e Tue Dec 17 10:55:02 2019 +0000 Christian Haeubl [GR-19974] Added a VM thread status.
c2ee5c253e6 Mon Dec 16 13:48:02 2019 +0000 Doug Simon [GR-20133] Update supported max java version to 15.
d3e8095b1a0 Sat Dec 14 10:39:12 2019 +0000 Tomáš Zezula [GR-19850] Merge Truffle runtime options systems into a single option system.
ba6eb12de63 Sat Dec 14 07:40:00 2019 +0000 Igor Veresov [GR-20076] Work around deprecation of ThreadLocalHandshakes.
008cfde3a69 Fri Dec 13 02:34:18 2019 +0000 Doug Simon [GR-20082] Verify usage of UserError.guarantee is as expected.
fbe27a00ab0 Thu Dec 12 23:16:42 2019 +0000 Stefan Anzinger [GR-16083] Merge two consecutive ldr/str to ldp/stp for AArch64.
098abdc9b87 Thu Dec 12 09:59:51 2019 +0000 David Leopoldseder [GR-19800] PE: fix typos.
874701eafbc Thu Dec 12 04:44:28 2019 +0000 Tom Rodriguez [GR-20003] Fix overriding of OptimisticOptimizations in unit tests.
abbbfb37745 Wed Dec 11 21:48:51 2019 +0000 Doug Simon [GR-19829] Make unit tests work on JDK 11 on Windows.
17a0c2940da Wed Dec 11 19:37:45 2019 +0000 Benoit Daloze [GR-19205] Use FULL_UNROLL_UNTIL_RETURN by default for @ExplodeLoop.