On SGI, we need to define _SGI_MP_SOURCE before including errno.h when we are threading, otherwise accessing errno doesn't work right.
On SGI, we need to define _SGI_MP_SOURCE before including errno.h when
we are threading, otherwise accessing errno doesn't work right.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator