This patch introdces 'checker' to decoding phase, and calls checkers
when instruction decoding. This allows further decoding for specific
instructions.  This patch introduces a stub call of checkers in kprobe
arch_prepare_kprobe() as an example and for further expansion.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Reviewed-by: NJon Medhurst <tixy@linaro.org>
Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NJon Medhurst <tixy@linaro.org>