pgsql: Work around perl bug in SvPVutf8().

Work around perl bug in SvPVutf8().

Certain things like typeglobs or readonly things like $^V cause
perl's SvPVutf8() to die nastily and crash the backend. To avoid
that bug we make a copy of the object, which will subsequently be
garbage collected.

Back patched to 9.1 where we first started using SvPVutf8().

Per -hackers discussion. Original problem reported by David Wheeler.

Branch
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REL9_1_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/d496384d6771c276a0253758418e7933b6f31167

Modified Files
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src/pl/plperl/plperl_helpers.h | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)