* Handle more cases in dead member elim
- Rewrite composite insert and extract operations on SpecConstnatOp.
- Leaves assert for Access chain instructions, which are only allowed
for kernels.
- Other operations do not require any extra code will no longer cause an
assert.
Fixes#3284.
Fixes#3282.
The types of input and output variables must match for the pipeline. We
cannot see the uses in all of the shader, so dead member
elimination cannot safely change the type of input and output variables.
Add a pass that looks for members of structs whose values do not affects
the output of the shader. Those members are then removed and just
treated like padding in the struct.
