Due to the left-prefix rule of indexes, for an index key to be usable,
it needs to:
- Use the columns in contiguous order (0, 1, 2...)
* eg if WHERE refers to cols 0 and 2, only 0 can be used
- Stop at the first range operator
* eg if WHERE: col1 = 5 AND col2 > 5 AND col3 = 5, only col1 and col2
can be used.
This wasn't properly tested, and resulted in simulator failures. Added
some regression tests for this behavior.
547ca6cf2a