Dynamically setting width format no longer working

[matias-eduardo]

After #3566, dynamically setting width in the following way stopped working:

fmt.printf(
    "[% -[1]*v][% -[3]*v][% -[5]*v][% -[7]*v][% -[9]*v]\n",
    6, "First",
    30, "Second",
    10, "Third",
    20, "Fourth",
    20, "Fifth",
)

// Expected output:
// [First ][Second                        ][Third     ][Fourth              ][Fifth               ]

// Current output:
// [%!*(string=First)v][%!*(string=Second)v][%!*(string=Third)v][%!*(string=Fourth)v][%!*(string=Fifth)v]