RFR(XS): Provide information when hitting a HaltNode for architectures other than x86

[Andrew Haley]

On 5/6/20 8:25 AM, Liu, Xin wrote:
>     Currently in AArch64 MacroAssembler::stop(), it will generate many
>     register saving instructions by pusha() before calling to debug64(). But
>     I think debug64() only uses the regs[] and pc arguments when
>     ShowMessageBoxOnError is on. Maybe we should at least only do the saving
>     and pc arg passing when ShowMessageBoxOnError is on in
>     MacroAssembler::stop(), as what x86 does in macroAssembler_x86.cpp?

Maybe we should think about a better way to do it. All we have
to do, after all, is put the reason into, say, r8, and execute
a trap. We don't need to push and pop anything because the trap
handler will do that.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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