pgsql: Update PG_CACHE_LINE_SIZE description.

Update PG_CACHE_LINE_SIZE description.

PG_CACHE_LINE_SIZE was originally only used in xlog.c, but this hasn't
been true for a very long time and is now wildly used, so modify its
description to not mention any explicit source code file.

Author: Julien Rouhaud
Discussion: https://www.postgresql.org/message-id/20230701074936.p3qcssl4t7murt2q@jrouhaud

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/dc6070bf5deec475b7efecaabf71eb9b49633973

Modified Files
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src/include/pg_config_manual.h | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)