In order to detect stack overflow, a few OS pages at the end of stack are marked inaccessible, as illustrated in `class StackOverflow`, i.e. "guard zone". Such guard pages are constructed in `StackOverflow::create_stack_guard_pages`, it consists of mainly two steps (calls):

1. os::create_stack_guard_pages -- some preparation work
2. os::guard_memory -- mark guard-pages as inaccessible

The postcondition is that those guard-pages should be inaccessible (i.e. raising OS signal on access).

Since those guard-pages are supposted to be inaccesible, we can use reserved-memory, instead of committed-memory. for them.

Implementatin note:

- Linux main thread reserves stack memory dynamically, so need to take special care in `create_stack_guard_pages` for it.

From https://man7.org/linux/man-pages/man3/pthread_attr_setstacksize.3.html
"""
       A thread's stack size is fixed at the time of thread creation.
       Only the main thread can dynamically grow its stack.
"""

- Windows requires committed-memory for guard-pages.

From https://learn.microsoft.com/en-us/windows/win32/api/memoryapi/nf-memoryapi-virtualprotect:

"You can set the access protection value on committed pages only."


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NMT currently mark stack guard pages are committed:

0x00007fc5b47f2000 - 0x00007fc5b48f3000] reserved 1028KB for Thread Stack from
    [0x00007fc60891e467] thread_native_entry(Thread*)+0xe7

        [0x00007fc5b47f2000 - 0x00007fc5b47f6000] committed 16KB from
            [0x00007fc608accb97] StackOverflow::create_stack_guard_pages()+0x57
            [0x00007fc608b8de01] JavaThread::run()+0x31
            [0x00007fc608b913fe] Thread::call_run()+0xde
            [0x00007fc60891e467] thread_native_entry(Thread*)+0xe7

but smaps says otherwise:

7fc5b47f2000-7fc5b47f6000 ---p 00000000 00:00 0
Size: 16 kB
KernelPageSize: 4 kB
MMUPageSize: 4 kB
Rss: 0 kB
Pss: 0 kB
Shared_Clean: 0 kB
Shared_Dirty: 0 kB
Private_Clean: 0 kB
Private_Dirty: 0 kB
Referenced: 0 kB
Anonymous: 0 kB
LazyFree: 0 kB
AnonHugePages: 0 kB
ShmemPmdMapped: 0 kB
FilePmdMapped: 0 kB
Shared_Hugetlb: 0 kB
Private_Hugetlb: 0 kB
Swap: 0 kB
SwapPss: 0 kB
Locked: 0 kB