re_intuit_start(): merge anch and float "other"

re_intuit_start(): merge anch and float "other"

When processing the "other" substring, there are two very similar
branches: one if "other" is anchored, the other if it's floating.
Merge these two branches.

The diff output makes it look a lot messier that it actually is; really
it's a bit like

    if (other_ix) {
        A;
        B1;
        C;
    }
    else {
        A;
        B2;
        C;
    }

becomes

    {
        A;
        if (other_ix)
            B1;
        else
            B2;
        C;
    }

where each statement such as B, that differs between the two branches,
is handled separately.