pgsql: Control ctype behavior internally with a method table.

Control ctype behavior internally with a method table.

Previously, pattern matching and case mapping behavior branched based
on the provider. Refactor to use a method table, which is less
error-prone.

This is also a step toward multiple provider versions, which we may
want to support in the future.

Reviewed-by: Andreas Karlsson <andreas(at)proxel(dot)se>
Reviewed-by: Peter Eisentraut <peter(at)eisentraut(dot)org>
Discussion: https://postgr.es/m/2830211e1b6e6a2e26d845780b03e125281ea17b.camel%40j-davis.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/5a38104b364234615c780656a8b2424f96ed9efa

Modified Files
--------------
src/backend/regex/regc_pg_locale.c | 429 ++++++------------------------
src/backend/utils/adt/like.c | 22 +-
src/backend/utils/adt/like_support.c | 7 +-
src/backend/utils/adt/pg_locale.c | 121 +++------
src/backend/utils/adt/pg_locale_builtin.c | 111 +++++++-
src/backend/utils/adt/pg_locale_icu.c | 119 ++++++++-
src/backend/utils/adt/pg_locale_libc.c | 331 ++++++++++++++++++++---
src/include/utils/pg_locale.h | 53 ++++
src/tools/pgindent/typedefs.list | 1 -
9 files changed, 686 insertions(+), 508 deletions(-)