WIP snapshot of hardware watchpoints for arm. A simple watchpoint has triggered.

However, the debugserver cannot get past the instruction which triggered the watchpoint.
So a workaround is in place for the time being which disables the triggered watchpoint
before resuming.

Lots of commented out printf's remain in the source which needs to be cleaned up.

WIP rdar://problem/9667960

llvm-svn: 153228