pgsql: Avoid index rebuild for no-rewrite ALTER TABLE .. ALTER TYPE.

Avoid index rebuild for no-rewrite ALTER TABLE .. ALTER TYPE.

Noah Misch. Review and minor cosmetic changes by me.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/367bc426a1c22b9f6badb06cd41fc438fd034639

Modified Files
--------------
doc/src/sgml/xindex.sgml | 9 +-
src/backend/bootstrap/bootparse.y | 3 +
src/backend/catalog/heap.c | 16 +++-
src/backend/catalog/index.c | 4 +
src/backend/catalog/storage.c | 11 +-
src/backend/catalog/toasting.c | 2 +-
src/backend/commands/indexcmds.c | 211 ++++++++++++++++++++++++++++++++++-
src/backend/commands/tablecmds.c | 114 ++++++++++++++------
src/backend/nodes/copyfuncs.c | 1 +
src/backend/nodes/equalfuncs.c | 1 +
src/backend/nodes/outfuncs.c | 1 +
src/backend/tcop/utility.c | 1 +
src/backend/utils/cache/relcache.c | 11 +-
src/backend/utils/cache/relmapper.c | 2 +-
src/include/catalog/heap.h | 1 +
src/include/catalog/index.h | 1 +
src/include/catalog/storage.h | 2 +-
src/include/commands/defrem.h | 8 +-
src/include/nodes/parsenodes.h | 1 +
src/include/utils/relcache.h | 1 +
20 files changed, 348 insertions(+), 53 deletions(-)