This check-in attempts to make the SrcItem object smaller by combining the

This check-in attempts to make the SrcItem object smaller by combining the
zDatabase and pSchema fields into a single union.  It mostly works, but there
are some issues, and the performance savings is minimal.  So it is side-tracked
onto this dead-end branch.

FossilOrigin-Name: 80fbb30f28c8a468d71a367968bb0c4b17cbc8080dff333a359fea09e9907550