pgsql: Handle PlaceHolderVar case in replace_varno_walker

Handle PlaceHolderVar case in replace_varno_walker

This commit also retires sje_walker.  This increases the generalty of replacing
varno in the parse tree and simplifies the code.

Discussion: https://postgr.es/m/18187-831da249cbd2ff8e%40postgresql.org
Author: Richard Guo
Reviewed-by: Andrei Lepikhov

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/8a8ed916f73f4f16e8eb3e0e30ac1201a7642fda

Modified Files
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src/backend/optimizer/plan/analyzejoins.c | 34 +++++++++++--------------------
1 file changed, 12 insertions(+), 22 deletions(-)