pgsql: amcheck: Refactoring the storage of the last visible entry

amcheck: Refactoring the storage of the last visible entry

This commit introduces a new data structure BtreeLastVisibleEntry comprising
information about the last visible heap entry with the current value of key.
Usage of this data structure allows us to avoid passing all this information
as individual function arguments.

Reported-by: Alexander Korotkov
Discussion:
https://www.postgresql.org/message-id/CAPpHfdsVbB9ToriaB1UHuOKwjKxiZmTFQcEF%3DjuzzC_nby31uA%40mail.gmail.com
Author: Pavel Borisov, Alexander Korotkov

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/532d94fec32ac11263b53932365560491d1fd50a

Modified Files
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contrib/amcheck/verify_nbtree.c  | 117 ++++++++++++++++++++-------------------
src/tools/pgindent/typedefs.list |   1 +
2 files changed, 60 insertions(+), 58 deletions(-)