pgsql: Allow users with BYPASSRLS to alter their own passwords.

Allow users with BYPASSRLS to alter their own passwords.

The intention in commit 491c029db was to require superuserness to
change the BYPASSRLS property, but the actual effect of the coding
in AlterRole() was to require superuserness to change anything at all
about a BYPASSRLS role.  Other properties of a BYPASSRLS role should
be changeable under the same rules as for a normal role, though.

Fix that, and also take care of some documentation omissions related
to BYPASSRLS and REPLICATION role properties.

Tom Lane and Stephen Frost, per bug report from Wolfgang Walther.
Back-patch to all supported branches.

Discussion: https://postgr.es/m/a5548a9f-89ee-3167-129d-162b5985fcf8@technowledgy.de

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/d907bd0543aa63e59653d7345840bed0f8b3a83b

Modified Files
--------------
doc/src/sgml/ref/alter_role.sgml  |  4 +++-
doc/src/sgml/ref/create_role.sgml | 11 +++++++++--
src/backend/commands/user.c       | 10 ++++++----
3 files changed, 18 insertions(+), 7 deletions(-)