pgsql: Rename RelationData.rd_amroutine to rd_indam.

Rename RelationData.rd_amroutine to rd_indam.

The upcoming table AM support makes rd_amroutine to generic, as its
only about index AMs. The new name makes that clear, and is shorter to
boot.

Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/346ed70b0ad7efc574711a97812692dab4542712

Modified Files
--------------
src/backend/access/index/indexam.c | 62 ++++++++++++++++++------------------
src/backend/catalog/index.c | 12 +++----
src/backend/commands/cluster.c | 2 +-
src/backend/commands/tablecmds.c | 4 +--
src/backend/executor/nodeIndexscan.c | 2 +-
src/backend/optimizer/util/plancat.c | 4 +--
src/backend/parser/parse_utilcmd.c | 2 +-
src/backend/utils/cache/relcache.c | 14 ++++----
src/include/utils/rel.h | 2 +-
9 files changed, 52 insertions(+), 52 deletions(-)