Remove unnecessary #includes.

In cdbcat.h, include only the header files that are actually needed for
the single function prototype in that file. And don't include cdbcat.h
unnecessarily. A couple of .c files were including cdbcat.h to get
GpPolicy, but that's actually defined in catalog/gp_policy.h, so #include
that directly instead where needed.

src/backend/cdb/cdbllize.c

@@ -35,7 +35,6 @@
 #include "cdb/cdbplan.h"
 #include "cdb/cdbpullup.h"
 #include "cdb/cdbllize.h"
-#include "cdb/cdbcat.h"
 #include "cdb/cdbmutate.h"
 #include "optimizer/tlist.h"
 

src/backend/cdb/cdbpathlocus.c

@@ -12,7 +12,7 @@
 extern "C" {
 #endif
 
-#include "cdb/cdbcat.h"         /* GpPolicy */
+#include "catalog/gp_policy.h"         /* GpPolicy */
 #include "cdb/cdbdef.h"         /* CdbSwap() */
 #include "cdb/cdbpullup.h"      /* cdbpullup_missing_var_walker() */
 #include "nodes/makefuncs.h"    /* makeVar() */

src/backend/cdb/cdbutil.c

@@ -29,7 +29,6 @@
 #include "utils/memutils.h"
 #include "catalog/gp_configuration.h"
 #include "catalog/gp_segment_config.h"
-#include "cdb/cdbcat.h"
 #include "cdb/cdbutil.h"
 #include "nodes/execnodes.h"	/* Slice, SliceTable */
 #include "cdb/cdbmotion.h"

src/backend/commands/dbcommands.c

@@ -66,7 +66,6 @@
 #include "cdb/cdbsreh.h"
 #include "cdb/cdbsrlz.h"
 #include "cdb/cdbvars.h"
-#include "cdb/cdbcat.h"
 #include "cdb/cdbpersistentdatabase.h"
 #include "cdb/cdbpersistentrelation.h"
 #include "cdb/cdbmirroredfilesysobj.h"

src/backend/commands/schemacmds.c

@@ -36,7 +36,6 @@
 #include "cdb/cdbdisp.h"
 #include "cdb/cdbsrlz.h"
 #include "cdb/cdbvars.h"
-#include "cdb/cdbcat.h"
 
 static void AlterSchemaOwner_internal(cqContext  *pcqCtx, 
 									  HeapTuple tup, Relation rel, Oid newOwnerId);

src/backend/commands/sequence.c

@@ -39,7 +39,6 @@
 #include "cdb/cdbdisp.h"
 #include "cdb/cdbsrlz.h"
 #include "cdb/cdbvars.h"
-#include "cdb/cdbcat.h"
 #include "cdb/cdbmotion.h"
 #include "cdb/ml_ipc.h"
 

src/backend/commands/tablecmds.c

@@ -110,7 +110,6 @@
 #include "cdb/cdbdisp.h"
 #include "cdb/cdbsrlz.h"
 #include "cdb/cdbvars.h"
-#include "cdb/cdbcat.h"
 #include "cdb/cdbrelsize.h"
 #include "cdb/cdboidsync.h"
 #include "cdb/cdbsreh.h"

src/backend/commands/user.c

@@ -45,7 +45,6 @@
 #include "cdb/cdbdisp.h"
 #include "cdb/cdbsrlz.h"
 #include "cdb/cdbvars.h"
-#include "cdb/cdbcat.h"
 
 
 typedef struct genericPair

src/backend/executor/execMain.c

@@ -82,7 +82,6 @@
 
 #include "cdb/cdbappendonlyam.h"
 #include "cdb/cdbaocsam.h"
-#include "cdb/cdbcat.h"
 #include "cdb/cdbdisp.h"
 #include "cdb/cdbdispatchresult.h"
 #include "cdb/cdbexplain.h"             /* cdbexplain_sendExecStats() */

src/backend/utils/cache/relcache.c

@@ -73,7 +73,7 @@
 #include "utils/syscache.h"
 #include "utils/typcache.h"
 
-#include "cdb/cdbcat.h"         /* GpPolicy */
+#include "catalog/gp_policy.h"         /* GpPolicy */
 #include "cdb/cdbtm.h"
 #include "cdb/cdbvars.h"        /* Gp_role */
 #include "cdb/cdbmirroredflatfile.h"

src/include/cdb/cdbcat.h

@@ -11,10 +11,8 @@
 #ifndef CDBCAT_H
 #define CDBCAT_H
 
-#include "access/genam.h"
-#include "access/heapam.h"
-#include "catalog/gp_id.h"
-#include "catalog/gp_policy.h"
+#include "access/attnum.h"
+#include "utils/relcache.h"
 
 extern void checkPolicyForUniqueIndex(Relation rel, AttrNumber *indattr,
 									  int nidxatts, bool isprimary,