Running "time bitbake -pP idle" with a valid cache shows around 800,000
calls to enum creation from python's signal.py. We don't care about this
overhead and it adversely affects cache load time quite badly.
Try and use _signal directly, falling back to signal, which avoids
this overhead we don't need and makes cache loading much faster.
(Bitbake rev: ee5fce67ce35b025c68aa61e2e758903269ee346)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
49d0abc5c8