pgsql: Combine options for RangeVarGetRelidExtended() into a flags argu

Combine options for RangeVarGetRelidExtended() into a flags argument.

A followup patch will add a SKIP_LOCKED option. To avoid introducing
evermore arguments, breaking existing callers each time, introduce a
flags argument. This'll no doubt break a few external users...

Also change the MISSING_OK behaviour so a DEBUG1 debug message is
emitted when a relation is not found.

Author: Nathan Bossart
Reviewed-By: Michael Paquier and Andres Freund
Discussion: https://postgr.es/m/20180306005349.b65whmvj7z6hbe2y@alap3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/d87510a524f36a630cfb34cc392e95e959a1b0dc

Modified Files
--------------
src/backend/catalog/namespace.c | 20 ++++++++++++--------
src/backend/commands/cluster.c | 2 +-
src/backend/commands/indexcmds.c | 4 ++--
src/backend/commands/lockcmds.c | 4 ++--
src/backend/commands/matview.c | 2 +-
src/backend/commands/policy.c | 6 +++---
src/backend/commands/sequence.c | 3 +--
src/backend/commands/tablecmds.c | 16 ++++++++--------
src/backend/commands/trigger.c | 2 +-
src/backend/rewrite/rewriteDefine.c | 2 +-
src/backend/tcop/utility.c | 2 +-
src/include/catalog/namespace.h | 14 ++++++++++++--
12 files changed, 45 insertions(+), 32 deletions(-)