pgsql: Verify that expected slot types match returned slot types.

Verify that expected slot types match returned slot types.

This is important so JIT compilation knows what kind of tuple slot the
deforming routine can expect. There's also optimization potential for
expression initialization without JIT compilation. It e.g. seems
plausible to elide EEOP_*_FETCHSOME ops entirely when dealing with
virtual slots.

Author: Andres Freund
Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/15d8f83128e15de97de61430d0b9569f5ebecc26

Modified Files
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src/backend/executor/execExprInterp.c | 52 +++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)