wgsl: Assignment with references and pointers

[dj2]

• [ ] Assignment to a pointer fails
• [ ] Assignment to a ref of access mode write fails
• [ ] Assignment to a ref of access more read or read_write passes
• [ ] Assignment of a RHS store type not matching LHS store type fails
• [ ] Assignment from a RHS with access more write fails
• [ ] Assignment to a LHS with is an indirection of a pointer passes *x = *x + 1
• [ ] Assignment to component of vector uv.x
• [ ] Assignment to multiple components of vector fails uv.xy
• [ ] Assignment to index of vector uv[0]
• [ ] Assignment of vector to index of matrix m[1]
• [ ] Assignment to index of value of matrix m[1][1]
• [ ] Assignment to array at index A[1]
• [ ] Assignment to structure entry by name p.name

4.5.3. Use Cases for References and Pointers