On MacOS, libraries have a couple of minor issues and, as a safety,
let's make sure no other library than the required library is loaded.

Change-Id: I376b77b3cf3f635ff57c12ccde2b9e84d4105adc
Reviewed-on: https://swiftshader-review.googlesource.com/17888Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>