Add more long benchmarks.

The added benchmarks distinguish between operations on
"big" longs (that require more than 54 bits to contain their
value) and "small" operations (that require less than 31 bits).

This patch preparses for changing GWT's / j2cl's long representation
to use pure JavaScript double values for representing small longs.
This way we won't incur the overhead of object allocation and
always dealing with 3 numbers on every long operation for
small long values.

Change-Id: I377c326ebed1bbe25dbc048f6a2e85d1b0e81c7e
27 files changed