Here is a snippet from the definition of long_lshift1() in longobject.c:

for (i = 0; i < wordshift; i++)
    z->ob_digit[i] = 0;
accum = 0;
for (i = wordshift, j = 0; j < oldsize; i++, j++) {
    accum |= (twodigits)a->ob_digit[j] << remshift;
    z->ob_digit[i] = (digit)(accum & PyLong_MASK);
    accum >>= PyLong_SHIFT;
}

There is no need for i = wordshift in the for loop initialization (it adds to the number of instructions) and I do not think it improves readability.

I don't think this requires a news entry or an issue?