Can we remove extra memset in BloomInitPage, GinInitPage and SpGistInitPage when we have it in PageInit?

Hi,

We are memset-ting the special space page that's already set to zeros
by PageInit in BloomInitPage, GinInitPage and SpGistInitPage. We have
already removed the memset after PageInit in gistinitpage (see the
comment there).  Unless I'm missing something, IMO they are redundant.
I'm attaching a small patch that gets rid of the extra memset calls.

While on it, I removed MAXALIGN(sizeof(SpGistPageOpaqueData)) in
SpGistInitPage because the PageInit will anyways align the
specialSize. This change is inline with other places (such as
BloomInitPage, brin_page_init GinInitPage, gistinitpage,
_hash_pageinit and so on) where we just pass the size of special space
data structure.

I didn't see any regression test failure on my dev system with the
attached patch.

Thoughts?

With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com