RFR (S) 8217994: os::print_hex_dump should be more resilient against unreadable memory

[Aleksey Shipilev]

On 1/29/19 6:01 PM, zgu at redhat.com wrote:
> Looks good to me.

Thanks.

> But you may need "default" switch to make some compilers happy.

It follows the form of the existing switch. I also think we never actually reach any default label
in those switches, because there is an entry switch that returns on default.

-Aleksey