Added new BITGET function, that returns true if and only if a specified bit in a long is set. This helps simulate bit fields in H2, which is an approach I'm using to significantly shrink database size.

reported by Alexander (vraimax2016)

since it breaks all the tests.

this reverts commit 37641c9a

Fix bug in picking the right index for INSERT..ON DUPLICATE KEY UPDATE when there are both UNIQUE and PRIMARY KEY constraints.

It's already implemented and working:
https://github.com/h2database/h2database/pull/150

(a) on modern platforms, it's way faster to call this
(b) its more accurate
(c) on my SSD, queries are fast enough the System.currentTimeMillis does
not provide a decent measurement