SmallIntFormatter: simplify implementation.

Drastically reduce the size of the SmallIntFormatter code.
This should make the code slightly slower, but reduce the
overall size of the generated library by about 48 kiB.

It is unlikely that the performance difference will be
noticeable on any existing system Chromium runs on.

Bug: NONE
Change-Id: I1faa6020c0e9a7cc61f0f274b9a2c4ab6701aece
Reviewed-on: https://chromium-review.googlesource.com/836554
Reviewed-by: Jungshik Shin <jshin@chromium.org>
Reviewed-by: Albert J. Wong <ajwong@chromium.org>
3 files changed