Handle the 'z' and 'Z' remote packets for manipulating hardware watchpoints. This could be expanded quite easily to support hardware or software breakpoints as well. https://sourceware.org/gdb/onlinedocs/gdb/Packets.html Reviewed by: cem, markj MFC after: 3 weeks Sponsored by: NetApp, Inc. Sponsored by: Klara, Inc. NetApp PR: 51 Differential Revision: https://reviews.freebsd.org/D29173