Re: ResourceOwner refactoring

It looks like this patch set needs a bit of surgery to adapt to the LLVM 
changes in 9dce22033d.  The cfbot is reporting compiler warnings about 
this, and also some crashes, which might also be caused by this.

I do like the updated APIs.  (Maybe the repeated ".DebugPrint = NULL, 
      /* default message is fine */" lines could be omitted?)

I like that one can now easily change the elog(WARNING) in 
ResourceOwnerReleaseAll() to a PANIC or something to get automatic 
verification during testing.  I wonder if we should make this the 
default if assertions are on?  This would need some adjustments to 
src/test/modules/test_resowner because it would then fail.