pgsql: Fix incorrect xmlschema output for types timetz and timestamptz.

Fix incorrect xmlschema output for types timetz and timestamptz.

The output of table_to_xmlschema() and allied functions includes
a regex describing valid values for these types ... but the regex
was itself invalid, as it failed to escape a literal "+" sign.

Report and fix by Renan Soares Lopes. Back-patch to all
supported branches.

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

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/068739fb4f345c8c922d72f2c8e15e9c0a75056d

Modified Files
--------------
src/backend/utils/adt/xml.c | 4 +-
src/test/regress/expected/xmlmap.out | 928 ++++++++++++++++++---------------
src/test/regress/expected/xmlmap_1.out | 10 +-
src/test/regress/sql/xmlmap.sql | 10 +-
4 files changed, 514 insertions(+), 438 deletions(-)