ZGC: Reduce mark stack usage

The following test failed in the JDK16 CI:

vmTestbase/gc/gctests/FinalizeLock/FinalizeLock.java

Here's a snippet from the log file:

#section:main
----------messages:(4/218)----------
command: main gc.gctests.FinalizeLock.FinalizeLock -Dm-
reason: User specified action: run main/othervm gc.gctests.FinalizeLock.FinalizeLock -Dm-
Mode: othervm [/othervm specified]
elapsed time (seconds): 369.405
----------configuration:(0/0)----------
----------System.out:(33/1821)*----------
Stress time: 120 seconds
Stress iterations factor: 1
Stress threads factor: 1
Stress runs factor: 1
Max memory: 2063597568
Sleep time: 500
Iterations: 0
Number of threads: 16
Run GC thread: false
Run mem diag thread: false
Run forever: false
Starting Thread[gc.gctests.FinalizeLock.FinalizeLock$GarbageCreator@5b46e7f,5,MainThreadGroup]
Starting Thread[gc.gctests.FinalizeLock.FinalizeLock$SyncMethodCaller@6013cb32,5,MainThreadGroup]
For random generator using seed: -8517640306877451010
To re-run test with same seed value please add "-Djdk.test.lib.random.seed=-8517640306877451010" to command line.
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=\\zMarkStackAllocator.cpp:102
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (t:\\workspace\\open\\src\\hotspot\\share\\gc\\z\\zMarkStackAllocator.cpp:102), pid=31220, tid=2580
# fatal error: Mark stack space exhausted. Use -XX:ZMarkStackSpaceLimit=<size> to increase the maximum number of bytes allocated for mark stacks. Current limit is 8192M.
#
# JRE version: Java(TM) SE Runtime Environment (16.0+33) (fastdebug build 16-ea+33-2205)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 16-ea+33-2205, mixed mode, sharing, tiered, z gc, windows-amd64)
# Core dump will be written. Default location: T:\\testoutput\\test-support\\jtreg_closed_test_hotspot_jtreg_vmTestbase_vm_gc_misc_closed\\scratch\\2\\hs_err_pid31220.mdmp
#
# An error report file with more information is saved as:
# T:\\testoutput\\test-support\\jtreg_closed_test_hotspot_jtreg_vmTestbase_vm_gc_misc_closed\\scratch\\2\\hs_err_pid31220.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
----------System.err:(0/0)----------
----------rerun:(41/7157)*----------

Here's the crashing thread's stack:

--------------- T H R E A D ---------------

Current thread (0x00000204fcdd5300): GCTaskThread "ZWorker#1" [stack: 0x0000003af0200000,0x0000003af0300000] [id=2580]

Stack: [0x0000003af0200000,0x0000003af0300000]
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [jvm.dll+0xaf6711]
V [jvm.dll+0xd22ab7]
V [jvm.dll+0xd243de]
V [jvm.dll+0xd24af4]
V [jvm.dll+0x4c58fd]
V [jvm.dll+0xd846eb]
V [jvm.dll+0xd84820]
V [jvm.dll+0xd840e6]
V [jvm.dll+0xd6c729]
V [jvm.dll+0xd80642]
V [jvm.dll+0xd8242c]
V [jvm.dll+0xd83a1e]
V [jvm.dll+0xd83536]
V [jvm.dll+0xd9c2b5]
V [jvm.dll+0xd67c09]
V [jvm.dll+0xca3dd4]
V [jvm.dll+0xaf505e]
C [ucrtbase.dll+0x214c2]
C [KERNEL32.DLL+0x17034]
C [ntdll.dll+0x4d0d1]

I don't know why the symbols are missing.

The test task has these JVM args:

-XX:+CreateCoredumpOnCrash -XX:+UseZGC