Prevent to use magic constants

Use macroses for definition amstrategies/amsupport fields instead of
hardcoded values.

Author: Nikolay Shaplov with addition for contrib/bloom

contrib/bloom/blutils.c

@@ -73,8 +73,8 @@ blhandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
-	amroutine->amstrategies = 1;
-	amroutine->amsupport = 1;
+	amroutine->amstrategies = BLOOM_NSTRATEGIES;
+	amroutine->amsupport = BLOOM_NPROC;
 	amroutine->amcanorder = false;
 	amroutine->amcanorderbyop = false;
 	amroutine->amcanbackward = false;

src/backend/access/gin/ginutil.c

@@ -35,7 +35,7 @@ ginhandler(PG_FUNCTION_ARGS)
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
 	amroutine->amstrategies = 0;
-	amroutine->amsupport = 6;
+	amroutine->amsupport = GINNProcs;
 	amroutine->amcanorder = false;
 	amroutine->amcanorderbyop = false;
 	amroutine->amcanbackward = false;

src/backend/access/gist/gist.c

@@ -57,7 +57,7 @@ gisthandler(PG_FUNCTION_ARGS)
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
 	amroutine->amstrategies = 0;
-	amroutine->amsupport = 9;
+	amroutine->amsupport = GISTNProcs;
 	amroutine->amcanorder = false;
 	amroutine->amcanorderbyop = true;
 	amroutine->amcanbackward = false;

src/backend/access/hash/hash.c

@@ -51,8 +51,8 @@ hashhandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
-	amroutine->amstrategies = 1;
-	amroutine->amsupport = 1;
+	amroutine->amstrategies = HTMaxStrategyNumber;
+	amroutine->amsupport = HASHNProcs;
 	amroutine->amcanorder = false;
 	amroutine->amcanorderbyop = false;
 	amroutine->amcanbackward = true;

src/backend/access/nbtree/nbtree.c

@@ -84,8 +84,8 @@ bthandler(PG_FUNCTION_ARGS)
 {
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
-	amroutine->amstrategies = 5;
-	amroutine->amsupport = 2;
+	amroutine->amstrategies = BTMaxStrategyNumber;
+	amroutine->amsupport = BTNProcs;
 	amroutine->amcanorder = true;
 	amroutine->amcanorderbyop = false;
 	amroutine->amcanbackward = true;

src/backend/access/spgist/spgutils.c

@@ -36,7 +36,7 @@ spghandler(PG_FUNCTION_ARGS)
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
 	amroutine->amstrategies = 0;
-	amroutine->amsupport = 5;
+	amroutine->amsupport = SPGISTNProc;
 	amroutine->amcanorder = false;
 	amroutine->amcanorderbyop = false;
 	amroutine->amcanbackward = false;

src/include/access/hash.h

@@ -239,6 +239,7 @@ typedef HashMetaPageData *HashMetaPage;
  *	Since we only have one such proc in amproc, it's number 1.
  */
 #define HASHPROC		1
+#define HASHNProcs		1
 
 
 /* public routines */

src/include/access/nbtree.h

@@ -454,6 +454,7 @@ typedef struct xl_btree_newroot
 
 #define BTORDER_PROC		1
 #define BTSORTSUPPORT_PROC	2
+#define BTNProcs			2
 
 /*
  *	We need to be able to tell the difference between read and write