pgsql: Remove jsonb_plperl test cases for Inf/NaN conversions.

Remove jsonb_plperl test cases for Inf/NaN conversions.

It turns out that old Perl versions (before about 5.10) don't have any
very reliable way to generate Inf or NaN numeric values.  Getting around
that would require way more work than is really justified to test the
code involved, so let's just drop these new test cases.

Discussion: https://postgr.es/m/28585.1525131438@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6594ee280383b7548b006e7f96c8d06137fced57

Modified Files
--------------
contrib/jsonb_plperl/expected/jsonb_plperl.out  | 22 +---------------------
contrib/jsonb_plperl/expected/jsonb_plperlu.out | 22 +---------------------
contrib/jsonb_plperl/sql/jsonb_plperl.sql       | 22 ----------------------
contrib/jsonb_plperl/sql/jsonb_plperlu.sql      | 22 ----------------------
4 files changed, 2 insertions(+), 86 deletions(-)