"java -XX:+PrintFlagsRanges -version" reports:

     intx VMThreadStackSize [ 0 ... 9007199254740991 ] {pd product} {default}

but "java -XX:VMThreadStackSize=9007199254740991 -version" results in:

# ./build/macosx-x86_64-normal-server-release/jdk/bin/java -XX:VMThreadStackSize=9007199254740991 -version
[0.006s][warning][os,thread] Failed to start thread - pthread_create failed (EAGAIN) for attributes: stacksize: 9007199254740992k, guardsize: 4k, detached.
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Cannot create worker GC thread. Out of system resources.
# An error report file with more information is saved as:
# /Volumes/Work/bugs/8195097/jdk11_rehn/hs_err_pid18970.log