5bfe4b93e1
Tighten the verifier for arith cast ops to disallow changing tensor dimensions, e.g., static to dynamic. After this change: * `arith.cast_op %x : tensor<4xi32> to tensor<4xf32>` remains valid * `arith.cast_op %x : tensor<4xi32> to tensor<?xf32>` becomes invalid * `arith.cast_op %x : tensor<?xi32> to tensor<4xf32>` becomes invalid This is mostly to simplify the op semantics. See the discussion thread for more context: https://discourse.llvm.org/t/rfc-remove-arith-math-ops-on-tensors/74357/63.