352a836176
This is a small canonicalization for `gep i32, p, (mul x, C)` -> `gep i8, p, (mul x, C*4)`, so that the mul can combine both of the constant multiplications, and we take a small step towards canonicalizing more geps to i8. It currently doesn't attempt to check for multiple uses on the mul, but that should be possible if it sounds better. Let me know what you think of the idea in general.