Volano 64bit from main/baseline ~ b07 reproducibly fails with SEGV,
generally in fewer than 24 repeat runs of VolanoTest client. Tests run
on Turnip (Solaris 9, with 4 cpus).

Stack trace:
  ---- called from signal handler with signal 11 (SIGSEGV) ------
  [11] oopDesc::follow_contents(this = 0xffffffff395ab210), line 247 in "oop.inline.hpp"
  [12] MarkSweep::follow_stack(), line 284 in "markSweep.cpp"
  [13] MarkSweep::follow_root(p = 0xffffffff7e7d71a8), line 274 in "markSweep.cpp"
  [14] MarkSweep::FollowRootClosure::do_oop(this = 0xffffffff7e795a20, p = 0xffffffff7e7d71a8), line 80 in "markSweep.hpp"
  [15] Universe::oops_do(f = 0xffffffff7e795a20), line 107 in "universe.cpp"
  [16] GenCollectedHeap::process_strong_roots(this = 0x1001c4478, level = 1, younger_gens_as_roots = 0, collecting_perm_gen = 1, cso = CSO_SystemClasses, older_gens = 0xffffffff7e795a20, not_older_gens = 0xffffffff7e795a20), line 342 in "genCollectedHeap.cpp"
  [17] MarkSweep::mark_sweep_phase1(level = 1, marked_for_unloading = 0, clear_all_softrefs = 0), line 487 in "markSweep.cpp"
  [18] MarkSweep::invoke_at_safepoint(level = 1, rp = 0x1001c49e8, clear_all_softrefs = 0), line 90 in "markSweep.cpp"
  [19] OneContigSpaceCardGeneration::collect(this = 0x1001c4998, full = 0, clear_all_soft_refs = 0, size = 0, is_large_noref = 0, is_tlab = 0), line 319 in "generation.cpp"
  [20] GenCollectedHeap::do_collection(this = 0x1001c4478, full = 0, clear_all_soft_refs = 0, size = 0, is_large_noref = 0, is_tlab = 0, max_level = 1, notify_ref_lock = 0), line 254 in "genCollectedHeap.cpp"
  [21] TwoGenerationCollectorPolicy::satisfy_failed_allocation(this = 0x1001c4400, size = 5U, is_large_noref = 0, is_tlab = 0, notify_ref_lock = 0), line 191 in "collectorPolicy.cpp"
  [22] GenCollectedHeap::satisfy_failed_allocation(this = 0x1001c4478, size = 5U, is_large_noref = 0, is_tlab = 0, notify_ref_lock = 0), line 321 in "genCollectedHeap.cpp"
  [23] VM_GenCollectForAllocation::doit(this = 0xfffffffefa2fe730), line 100 in "vm_operations.cpp"
  [24] VM_Operation::evaluate(this = 0xfffffffefa2fe730), line 26 in "vm_operations.cpp"
  [25] VMThread::evaluate_operation(this = 0x10021d948, op = 0xfffffffefa2fe730), line 252 in "vmThread.cpp"
  [26] VMThread::loop(this = 0x10021d948), line 328 in "vmThread.cpp"
  [27] VMThread::run(this = 0x10021d948), line 183 in "vmThread.cpp"