Re: Allow CLUSTER, VACUUM FULL and REINDEX to change tablespace on the fly

A side comment on this patch: I think using enums as bit mask values is
bad style. So changing this:

-/* Reindex options */
-#define REINDEXOPT_VERBOSE (1 << 0) /* print progress info */
-#define REINDEXOPT_REPORT_PROGRESS (1 << 1) /* report pgstat progress */
-#define REINDEXOPT_MISSING_OK (1 << 2) /* skip missing relations */
-#define REINDEXOPT_CONCURRENTLY (1 << 3) /* concurrent mode */

to this:

+typedef enum ReindexOption
+{
+ REINDEXOPT_VERBOSE = 1 << 0, /* print progress info */
+ REINDEXOPT_REPORT_PROGRESS = 1 << 1, /* report pgstat progress */
+ REINDEXOPT_MISSING_OK = 1 << 2, /* skip missing relations */
+ REINDEXOPT_CONCURRENTLY = 1 << 3 /* concurrent mode */
+} ReindexOption;

seems wrong.

There are a couple of more places like this, including the existing
ClusterOption that this patched moved around, but we should be removing
those.

My reasoning is that if you look at an enum value of this type, either
say in a switch statement or a debugger, the enum value might not be any
of the defined symbols. So that way you lose all the type checking that
an enum might give you.

Let's just keep the #define's like it is done in almost all other places.