kmv-all.c: remove pointless malloc check in breakpoint fn

A failure to g_malloc would abort anyway.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
target-arm: KVM Headers (WIP)

I assume I'll properly merge the KVM Headers direct from Linux when done.

---
v2
  - more stuff
v3
  - even more
target-arm: kvm - implement software breakpoints

These don't involve messing around with debug registers, just setting
the breakpoint instruction in memory. GDB will not use this mechanism if
it can't access the memory to write the breakpoint.

--
v2
  - add CAP check
  - add enable debug for SW breakpoints
v3
  - properly handle handle_arch_exit/debug
target-arm: kvm support for single step
target-arm: kvm - add support for HW assisted debug (INCOMP)

This adds basic support for HW assisted debug. The ioctl interface to
KVM allows us to pass an implementation defined number of break and
watch point registers. When KVM_GUESTDBG_USE_HW_BP is specified these
debug registers will be installed in place on the world switch into the
guest.

The hardware is actually capable of more advanced matching but it's
unclear if this expressiveness is available via the gdbstub protocol.
However it wouldn't be hard to add at a later date.