rbigint.py improvements

Closed Bitbucket Importer requested to merge bitbucket/declined-pr-71 into branch/default

Created originally on Bitbucket by _stian (Stian Andreassen)

Changesets for this Pull Request have not been imported, because it had been already declined on Bitbucket. Marked as closed by the import user.

Speed up rbigint operations by everything from 5% to 40% (I managed to get one pow test down from 17.8s to 10.2s). It also add some special cases for BIGINT0, BIGINT1, BIGINT*powerOfTwo, BIGINT-BIGINT and BIGINT+BIGINT (these things happends internally on all operations, so it causes a general speed gain).

Haven't tried any benchmark out of rpython.

Merge request reports