Re: Getting rid of pre-assignment of index names in CREATE TABLE LIKE

While I was at it, it seemed like DefineIndex's parameter list had grown
well past any sane bound, so I refactored it to pass the IndexStmt
struct as-is rather than passing all the fields individually.

With or without that choice, though, this approach means a change in
DefineIndex's API, as well as the contents of struct IndexStmt.  That
means it's probably unsafe to back-patch, since it seems plausible that
there might be third-party code out there that creates indexes and would
use these interfaces.

I would like to sneak this fix into 9.2, though.  Does anyone think
it's already too late to be touching these APIs for 9.2?