pgsql: Make hstore_plperl's build even more like plperl's

Make hstore_plperl's build even more like plperl's

Combine the two places that set CPPFLAGS into one.  Also, some settings
should be restricted to Windows only.  More precisely, -Wno-comment is
a GCC-only option, but Windows in a makefile implies GCC at the moment.

Also, since -Wno-comment is more properly a preprocessor option, move it
to CPPFLAGS to simplify things a bit.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/0fd764647a9910a340359bb319929b70317b2ae4

Modified Files
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contrib/hstore_plperl/Makefile |   10 ++++++----
src/pl/plperl/GNUmakefile      |    2 +-
2 files changed, 7 insertions(+), 5 deletions(-)