pgsql: ICU: do not convert locale 'C' to 'en-US-u-va-posix'.

ICU: do not convert locale 'C' to 'en-US-u-va-posix'.

The conversion was intended to be for convenience, but it's more
likely to be confusing than useful.

The user can still directly specify 'en-US-u-va-posix' if desired.

Discussion: https://postgr.es/m/[email protected]
Discussion: https://postgr.es/m/[email protected]

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/f7faa9976cc0504c027a20ed66ceca9018041dd4

Modified Files
--------------
src/backend/utils/adt/pg_locale.c | 19 +------------------
src/bin/initdb/initdb.c | 17 +----------------
src/test/regress/expected/collate.icu.utf8.out | 8 ++++++++
src/test/regress/sql/collate.icu.utf8.sql | 4 ++++
4 files changed, 14 insertions(+), 34 deletions(-)