Matrix layout qualifiers are valid for non-matrices Uniform block members may be structs containing matrices, and there's no explicit mention in the spec that the matrix qualifiers would only be valid for matrix fields. Only generate a warning when an extraneous matrix layout qualifier is used. TEST=dEQP-GLES3.functional.shaders.*layout* (all pass with this patch) BUG=angleproject:1058 Change-Id: Ifb2f2392d84100d997cc2d68fd55e9ad17a17cea Reviewed-on: https://chromium-review.googlesource.com/284112 Reviewed-by: Zhenyao Mo <zmo@chromium.org> Tested-by: Olli Etuaho <oetuaho@nvidia.com>