RFR (XS) 8247860: Shenandoah: add update watermark line in rich assert failure message

[Aleksey Shipilev]

RFE:
  https://bugs.openjdk.java.net/browse/JDK-8247860

Patch:

diff -r dbd95dd97289 src/hotspot/share/gc/shenandoah/shenandoahAsserts.cpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahAsserts.cpp     Tue Jun 16 15:18:58 2020 -0400
+++ b/src/hotspot/share/gc/shenandoah/shenandoahAsserts.cpp     Thu Jun 18 18:23:27 2020 +0200
@@ -68,4 +68,5 @@
   msg.append("  " PTR_FORMAT " - klass " PTR_FORMAT " %s\n", p2i(obj), p2i(obj->klass()),
obj->klass()->external_name());
   msg.append("    %3s allocated after mark start\n", ctx->allocated_after_mark_start(obj) ? "" :
"not");
+  msg.append("    %3s after update watermark\n",     cast_from_oop<HeapWord*>(obj) >=
r->get_update_watermark() ? "" : "not");
   msg.append("    %3s marked \n",                    ctx->is_marked(obj) ? "" : "not");
   msg.append("    %3s in collection set\n",          heap->in_collection_set(obj) ? "" : "not");

Testing: hotspot_gc_shenandoah

-- 
Thanks,
-Aleksey