RFR: Fix aarch64 after merge

[Roman Kennke]

This moves code around in aarch64 to account for yesterday merge.

http://cr.openjdk.java.net/~rkennke/fix-merge-aarch64/webrev.00/

There are two backportable changes that fix actual issues:
- c1_LIRGenerator.cpp to fix assert in TestSelectiveBarrierFlags.java
makes C1 barrier generation more consistent with interpreter and other
places
- write-barrier checking for EVACUATION | PARTIAL | TRAVERSAL instead of
just EVACUATION fixes partial+traversal modes

those have been broken before. the latter one doesn't easily fit jdk<11
because code moved to ShenandoahBarrierSetAssembler.

Testing: hotspot_gc_shenandoah only fires timeouts now. need to
investigate if it's actual bugs or just slow execution

Ok?

Roman