[COMMITTERS] pgsql: PL/Perl portability fix: avoid including XSUB.h in plperl.c.

PL/Perl portability fix: avoid including XSUB.h in plperl.c.

Back-patch of commit bebe174bb4462ef079a1d7eeafb82ff969f160a4,
which see for more info.

Patch by me, with some help from Ashutosh Sharma

Discussion: https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com

Branch
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REL9_5_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/99eea89dbe31fbd78d08a56e53f5bc272bbcd064

Modified Files
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contrib/hstore_plperl/hstore_plperl.c |   6 +-
src/pl/plperl/SPI.xs                  |  32 +----
src/pl/plperl/Util.xs                 |  44 +-----
src/pl/plperl/plperl.c                | 244 +++++++++++++++++++++++++---------
src/pl/plperl/plperl.h                |  17 ++-
src/pl/plperl/plperl_helpers.h        |   4 +
6 files changed, 210 insertions(+), 137 deletions(-)