scf-for-loop-range-folding does not multiply lower bound

[superlopuh]

Minimal example:

func.func private @foo(index) -> ()

%c0 = arith.constant 0 : index
%c1 = arith.constant 1 : index
%c2 = arith.constant 2 : index
%c3 = arith.constant 3 : index
%c6 = arith.constant 6 : index

scf.for %i = %c1 to %c6 step %c2 {
    %val = arith.muli %i, %c3 : index
    func.call @foo(%val) : (index) -> ()
}

// mlir-opt --scf-for-loop-range-folding --canonicalize

func.func private @foo(index)

%c6 = arith.constant 6 : index
%c18 = arith.constant 18 : index
%c1 = arith.constant 1 : index

scf.for %arg0 = %c1 to %c18 step %c6 {
  func.call @foo(%arg0) : (index) -> ()
}

In Python syntax:

a = [i * 3 for i in range(1, 6, 2)]
b = list(range(3, 18, 6))

Both a and b are [3, 9, 15]