pgsql: Update contrib/trgm_regexp's memory management.

Update contrib/trgm_regexp's memory management.

While no code change was necessary for this code to keep working, we
don't need to use PG_TRY()/PG_FINALLY() with explicit clean-up while
working with regexes anymore.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKGK3PGKwcKqzoosamn36YW-fsuTdOPPF1i_rtEO%3DnEYKSg%40mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6db75edb2ecbc9f6912f90b671b01ab4ac3a01b0

Modified Files
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contrib/pg_trgm/trgm_regexp.c | 17 ++---------------
1 file changed, 2 insertions(+), 15 deletions(-)