examples/matrix1: remove 32bit SPIR binaries, and make tests use explicit binary paths
examples/matrix1: remove 32bit SPIR binaries, and make tests use explicit binary paths

.. to avoid conflicting files between tests running in parallel

pocl/pocl,franz/pocl,pocl/pocl,franz/pocl,franz/pocl,pocl/pocl,pocl/pocl,franz/pocl,pocl/pocl,franz/pocl