pgsql: Consistently use named parameters in regex code.

Consistently use named parameters in regex code.

Make regex code consistently use named parameters in function
declarations.  Also make sure that parameter names from each function's
declaration match corresponding definition parameter names.

This makes Henry Spencer's regex code follow Postgres coding standards.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAH2-WznJt9CMM9KJTMjJh_zbL5hD9oX44qdJ4aqZtjFi-zA3Tg@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/bc2187ed63c56bb9cd99f6613f3e2ba56afb22fe

Modified Files
--------------
src/backend/regex/regcomp.c              | 342 +++++++++++++++++--------------
src/backend/regex/regexec.c              |  65 +++---
src/backend/utils/adt/regexp.c           |   2 +-
src/include/regex/regex.h                |  14 +-
src/test/modules/test_regex/test_regex.c |   2 +-
5 files changed, 241 insertions(+), 184 deletions(-)