[QoL] Change ValueRange to ResultRange in gate_op's result getters

[paul0403]

We have some convenience result/operand getters for gate operations, and currently they all return ValueRange.

Nothing is inherently wrong with this, but ResultRange has the replace methods built-in, and ValueRange does not.

To avoid manually casting or looping, we can change the result getters to return ResultRange directly, or provide an overloaded result getter.

[dime10]

The location the link is pointing to doesn't really make sense to me, but that might be because it's not a permalink. This (among other methods seems more sensible to me):

catalyst/mlir/include/Quantum/IR/QuantumOps.td

Line 286 in 4ec0a4e

mlir::ValueRange getNonCtrlQubitResults() {

[paul0403]

Hi @sengthai , we can chat more when I get back, but just quickly, here is an example of a place where I needed to do a manual loop to replace uses of a[i] with b[i] for all i for two ValueRanges a, b.

Ideally, with ResultRange's built-in replacement methods, only the one-line a.replaceAllUsesWith(b) will be necessary!