Adds stub socket functions to NaCl IO
Stub functions have been created for all the socket functions we plan
to implement. Noel wrote these, and then gave ownership to me. These are
supported in the glibc toolchain only, as we're holding off on making header
files for the other toolchains until we've decided what to do about
copyright issues.
BUG=257723
TEST=None
R=noelallen@chromium.org,bradnelson@google.com
Review URL: https://chromiumcodereview.appspot.com/
20141005
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@214557 0039d316-1c4b-4281-b951-d872f2087c98