Code clean for pre-9.0 binary upgrades in HeapTupleSatisfiesXXX()

Hi hackers,

When I read the heapam_visibility.c, I found that there is some code in
HeapTupleSatisfiesXXX that has a similar code for pre-9.0 binary upgrades.

HeapTupleSatisfiesSelf, HeapTupleSatisfiesToast and HeapTupleSatisfiesDirty
have the same code for pre-9.0 binary upgrades.  HeapTupleSatisfiesUpdate
has a similar code, except it returns TM_Result other than boolean.

HeapTupleSatisfiesMVCC also has a similar code like HeapTupleSatisfiesSelf,
expect it use XidInMVCCSnapshot other than TransactionIdIsInProgress.

The most different is HeapTupleSatisfiesVacuumHorizon.

Could we encapsulate the code for pre-9.0 binary upgrades?  This idea comes from [1].

Any thoughts?


[1] https://www.postgresql.org/message-id/8a855f33-2581-66bf-85f7-0b99239edbda%40postgrespro.ru

-- 
Regrads,
Japin Li.
ChengDu WenWu Information Technology Co.,Ltd.