spirv: Ignore ArrayStride in OpPtrAccessChain for Workgroup
From OpPtrAccessChain description in the SPIR-V spec (1.4 rev 1): For objects in the Uniform, StorageBuffer, or PushConstant storage classes, the element’s address or location is calculated using a stride, which will be the Base-type’s Array Stride when the Base type is decorated with ArrayStride. For all other objects, the implementation will calculate the element’s address or location. For non-CL shaders the driver should layout the Workgroup storage class, so override any explicitly set ArrayStride in the shader. This currently fixes only the lower_workgroup_access_to_offsets case, which is used by anv. Reviewed-by:Juan A. Suarez <jasuarez@igalia.com> (cherry picked from commit 050eb638)