sizebitvec of tsearch2, as well as identical code in several other
contrib modules. This provided about a 20X speedup in building a
large tsearch2 index ... didn't try to measure its effects for other
operations. Thanks to Stephan Vollmer for providing a test case.
boxes. Change interface to user-defined GiST support methods union and
picksplit. Now instead of bytea struct it used special GistEntryVector
structure.