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.