pgsql: Avoid JIT-related test instability in EXPLAIN ANALYZE

Avoid JIT-related test instability in EXPLAIN ANALYZE

036bdcec9 added some code to perform some verification on portions of
the planner costs in EXPLAIN ANALYZE but failed to consider that some
buildfarm animals such as bushmaster and taipan are running very low jit
thresholds.  This caused these animals to fail as they were outputting
JIT-related details in EXPLAIN ANALYZE for the newly added tests.

Here we avoid that by disabling JIT for the plans in question.

Discussion: https://postgr.es/m/CAApHDvpxV4rrO3XUCgGS5N9Wg6f2r0ojJPD2tX2FRV-o9sRTJA@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/c048cd992c69ed20acbd9059763735e51781e95a

Modified Files
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src/test/regress/expected/misc_functions.out | 3 +++
src/test/regress/sql/misc_functions.sql      | 3 +++
2 files changed, 6 insertions(+)