pgsql: Used optimized linear search in more code paths

Used optimized linear search in more code paths

This commit updates two code paths to use pg_lfind32() introduced by
b6ef167 with TransactionId arrays:
- At the end of TransactionIdIsInProgress(), when checking for the case
of still running but overflowed subxids.
- XidIsConcurrent(), when checking for a serializable conflict.

These cases are less impactful than 37a6e5d, but a bit of
micro-benchmarking of this API shows that linear search speeds up by
~20% depending on the number of items involved (x86_64 and amd64 looked
at here).

Author: Nathan Bossart
Reviewed-by: Richard Guo, Michael Paquier
Discussion: https://postgr.es/m/20220901185153.GA783106@nathanxps13

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/14ff44f80c09718d43d853363941457f5468cc03

Modified Files
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src/backend/storage/ipc/procarray.c  | 12 ++++--------
src/backend/storage/lmgr/predicate.c | 10 ++--------
2 files changed, 6 insertions(+), 16 deletions(-)