Add sampler2DMSArray support to HLSL output This is done with small adjustments to TextureFunctionHLSL. Most of the functionality was already in place before. This changes the categorization of sampler types in BasicTypes.h helper functions: 2D array samplers are no longer treated as 2D samplers, but the two categories are now entirely disjoint. This makes TextureFunctionHLSL a little bit simpler. BUG=angleproject:2775 TEST=angle_unittests, angle_end2end_tests Change-Id: I84d9b56c37b1aaa01ee5921b6f17f8a78698fce2 Reviewed-on: https://chromium-review.googlesource.com/1188562 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>