pgsql: Turn HeapKeyTest macro into inline function

Turn HeapKeyTest macro into inline function

It is easier to read as a function.

Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion:
https://www.postgresql.org/message-id/flat/CAAKRu_YSOnhKsDyFcqJsKtBSrd32DP-jjXmv7hL0BPD-z0TGXQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4eb3b11200010bf1342e51ff0f2622bba0e05c0c

Modified Files
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src/backend/access/heap/heapam.c |  8 ++--
src/include/access/valid.h       | 81 +++++++++++++++++-----------------------
2 files changed, 39 insertions(+), 50 deletions(-)