[DAG] Fold add(mul(add(A, CA), CM), CB) -> add(mul(A, CM), CM*CA+CB) (#90860)

This is useful when the inner add has multiple uses, and so cannot be
canonicalized by pushing the constants down through the mul. This patch
adds patterns for both `add(mul(add(A, CA), CM), CB)` and with an extra add
`add(add(mul(add(A, CA), CM), B) CB)` as the second can come up when
lowering geps.