[Bug libgcc/103510] _Unwind_GetGR crashed for uninitialized registers

[ashimida at linux dot alibaba.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103510

--- Comment #1 from ashimida <ashimida at linux dot alibaba.com> ---
For example, such a c code works find in clang with libunwind,
and will cause a crash in gcc with libgcc in aarch64.

#include <stdio.h>
#include <stdlib.h>
#include <unwind.h>

_Unwind_Reason_Code callback(struct _Unwind_Context *context, void *args)
{
        printf("Unwind Frame X0:%016lx\n", _Unwind_GetGR(context, 0));
        return _URC_NO_REASON;
}

int main(void)
{
        _Unwind_Backtrace(callback, NULL);
        return 0;
}