As agreed in the WG calls, the query tests are sufficient to cover
both old-style and new-style sampler and command queue creation
entrypoints.
Use old-style entrypoints in all tests that don't require 2.x
features to get compatibility with 1.x implementations.
This makes it possible to remove duplicate compatibility tests.
Contributes to #494.
Signed-off-by: Kévin Petit <kpet@free.fr>