With these changes, the "happy path" when the leading and trailing
number of bits don't need an update, fewer operations are needed.
The change is probably very marginal (no change in the benchmark added
here, but the benchmark also doesn't cover non-changing values), and
an argument could me made that avoiding pointers also has its
benefits.
However, I think that reducing the number of return values improves
readability. Which convinced me that I should at least propose this.
Signed-off-by: beorn7 <beorn@grafana.com>
