qom: Add cpu_exec_interrupt hook

Continuing the removal of ifdefs from cpu_exec.

Cc: Andreas Färber <afaerber@suse.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-xtensa: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-s390x: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-m68k: Use cpu_exec_interrupt qom hook

Since do_interrupt_m68k_hardirq is no longer used outside
op_helper.c, make it static.

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-cris: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-alpha: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-sh4: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-unicore32: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-arm: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-sparc: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-openrisc: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-tricore: Remove the dummy interrupt boilerplate

It can go back in when it actually does something.

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-mips: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-microblaze: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-lm32: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-ppc: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: Use cpu_exec_interrupt qom hook

Signed-off-by: Richard Henderson <rth@twiddle.net>
cpu-exec: Do CPU_INTERRUPT_HALT unconditionally

The signal is currently checked by 10 targets, but only actually
raised by Sparc and ARM.  For the sake of one test-and-branch,
we can handle this generic bit generically.

Signed-off-by: Richard Henderson <rth@twiddle.net>