The fix for JDK-8034852 added an assert:

Internal Error (/opt/jprt/T/P1/080804.ehelin/s/src/share/vm/memory/metaspace.cpp:1436), pid=25676, tid=39
assert(capacity_until_gc >= committed_bytes) failed: capacity_until_gc: 52428800 < committed_bytes: 52690944

that fails for a lot of cases. The problem is in MetaspaceGC::allowed_expansion:
  // Always grant expansion if we are initiating the JVM,
  // or if the GC_locker is preventing GCs.
  if (!is_init_completed() || GC_locker::is_active_and_needs_gc()) {
    return left_until_max / BytesPerWord;
  }

This will cause committed to grow beyond the HWM during initialization and when the GC_locker is active.

The change JDK-8034852 should be backed out until this problem has been solved.