Continuing to scrub aarch64-port changes against 8u upstream. Here is a funny bit in chaitin.hpp:
  https://builds.shipilev.net/patch-openjdk-jdk8-aarch64/hotspot/src/share/vm/opto/chaitin.hpp.sdiff.html

I think this is what happened:
 1. Change A got in:
     http://hg.openjdk.java.net/aarch64-port/jdk8u-shenandoah/hotspot/rev/c53f2cffc0f4#l10.6
 2. Change A got backed out:
     http://hg.openjdk.java.net/aarch64-port/jdk8u-shenandoah/hotspot/rev/5d458891a9ae#l10.6
 3. Merge happened, and Ed chose the wrong side of it for that particular block:
     http://hg.openjdk.java.net/aarch64-port/jdk8u-shenandoah/hotspot/rev/69403274d781#l236.51

Fix is trivial, just revert it back:

diff -r f255fe444394 src/share/vm/opto/chaitin.hpp
--- a/src/share/vm/opto/chaitin.hpp Thu Jul 18 17:11:19 2019 +0200
+++ b/src/share/vm/opto/chaitin.hpp Fri Jul 19 00:08:53 2019 +0200
@@ -322,8 +322,5 @@
 
   uint live_range_id(const Node *node) const {
- if (node->_idx >= size())
- return 0;
- else
- return _names.at(node->_idx);
+ return _names.at(node->_idx);
   }