pgsql: Introduce ExecQualAndReset() helper.

Introduce ExecQualAndReset() helper.

It's a common task to evaluate a qual and reset the corresponding
expression context. Currently that requires storing the result of the
qual eval, resetting the context, and then reacting on the result. As
that's awkward several places only reset the context next time through
a node. That's not great, so introduce a helper that evaluates and
resets.

It's a bit ugly that it currently uses MemoryContextReset() instead of
ResetExprContext(), but that seems easier than reordering all of
executor.h.

Author: Andres Freund
Discussion: https://postgr.es/m/20180109222544.f7loxrunqh3xjl5f@alap3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/c12693d8f3bbbffcb79f6af476cc647402e1145e

Modified Files
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src/backend/executor/nodeBitmapHeapscan.c | 9 ++-------
src/backend/executor/nodeHash.c | 10 ++--------
src/backend/executor/nodeIndexonlyscan.c | 3 +--
src/backend/executor/nodeIndexscan.c | 11 +++--------
src/include/executor/executor.h | 17 +++++++++++++++++
5 files changed, 25 insertions(+), 25 deletions(-)