<signal.h> shouldn't get you the contents of <errno.h>, and <fcntl.h>
shouldn't get you the contents of <unistd.h>.
Change-Id: I347499cd8671bfee98e6b8e875a97cab3a3655d3
It's safe to fix our constant definitions because we know we never
had symbols before, so can't be passing the bad old constants to the new
functions, or the correct new constants to the old inlines.
Change-Id: I858fc680df39bdd3ba471e867833bdfa71f6224e