pgsql: Consolidate DROP handling for some object types.

Consolidate DROP handling for some object types.

This gets rid of a significant amount of duplicative code.

KaiGai Kohei, reviewed in earlier versions by Dimitri Fontaine, with
further review and cleanup by me.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/82a4a777d94bec965ab2f1d04b6e6a3f0447b377

Modified Files
--------------
src/backend/catalog/objectaddress.c | 205 ++++++++++++++++++---------
src/backend/commands/Makefile | 2 +-
src/backend/commands/collationcmds.c | 61 --------
src/backend/commands/conversioncmds.c | 61 --------
src/backend/commands/dropcmds.c | 147 +++++++++++++++++++
src/backend/commands/extension.c | 63 --------
src/backend/commands/schemacmds.c | 63 --------
src/backend/commands/tsearchcmds.c | 254 ---------------------------------
src/backend/commands/typecmds.c | 92 ------------
src/backend/tcop/utility.c | 65 ++-------
src/include/catalog/objectaddress.h | 2 +
src/include/commands/collationcmds.h | 1 -
src/include/commands/conversioncmds.h | 1 -
src/include/commands/defrem.h | 6 +-
src/include/commands/extension.h | 1 -
src/include/commands/schemacmds.h | 1 -
src/include/commands/typecmds.h | 1 -
17 files changed, 300 insertions(+), 726 deletions(-)