Merge commit '121afa9e0c02617c2a774996512e4f85f3e93da8' into upstream-merge

Merge commit '121afa9e0c02617c2a774996512e4f85f3e93da8' into upstream-merge

* commit '121afa9e0c02617c2a774996512e4f85f3e93da8': (85 commits)
  Revert "Add ability to disable build of all targets"
  cpu_physical_memory_write_rom() needs to do TB invalidates
  qemu-char: BUGFIX, don't call FD_ISSET with negative fd
  Revert 455aa1e08 and c3767ed0eb
  pc: Drop practically unused BOCHS BIOS debug ports
  add -machine mem-merge=on|off option
  Remove unused CONFIG_TCG_PASS_AREG0 and dead code
  target-mips: switch to AREG0 free mode
  target-sh4: switch to AREG0 free mode
  target-cris: Switch to AREG0 free mode
  target-cris: Avoid AREG0 for helpers
  target-microblaze: switch to AREG0 free mode
  target-arm: final conversion to AREG0 free mode
  target-arm: convert remaining helpers
  target-arm: convert void helpers
  target-unicore32: switch to AREG0 free mode
  target-m68k: avoid using cpu_single_env
  target-m68k: switch to AREG0 free mode
  target-lm32: switch to AREG0 free mode
  target-s390x: avoid cpu_single_env
  ...

Conflicts:
	configure

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>