Remove obsolete cases from GiST update redo code.

The code that generated a record to clear the F_TUPLES_DELETED flag hasn't
existed since we got rid of old-style VACUUM FULL. I kept the code that sets
the flag, although it's not used for anything anymore, because it might
still be interesting information for debugging purposes that some tuples
have been deleted from a page.

Likewise, the code to turn the root page from non-leaf to leaf page was
removed when we got rid of old-style VACUUM FULL. Remove the code to replay
that action, too.

src/backend/access/gist/gistxlog.c

@@ -125,26 +125,6 @@ gistRedoPageUpdateRecord(XLogRecPtr lsn, XLogRecord *record)
 				off++;
 			}
 		}
-		else
-		{
-			/*
-			 * special case: leafpage, nothing to insert, nothing to delete,
-			 * then vacuum marks page
-			 */
-			if (GistPageIsLeaf(page) && xldata->ntodelete == 0)
-				GistClearTuplesDeleted(page);
-		}
-
-		if (!GistPageIsLeaf(page) &&
-			PageGetMaxOffsetNumber(page) == InvalidOffsetNumber &&
-			xldata->blkno == GIST_ROOT_BLKNO)
-		{
-			/*
-			 * all links on non-leaf root page was deleted by vacuum full, so
-			 * root page becomes a leaf
-			 */
-			GistPageSetLeaf(page);
-		}
 
 		PageSetLSN(page, lsn);
 		MarkBufferDirty(buffer);

src/include/access/gist.h

@@ -147,8 +147,6 @@ typedef struct GISTENTRY
 
 #define GistPageIsLeaf(page)	( GistPageGetOpaque(page)->flags & F_LEAF)
 #define GIST_LEAF(entry) (GistPageIsLeaf((entry)->page))
-#define GistPageSetLeaf(page)	( GistPageGetOpaque(page)->flags |= F_LEAF)
-#define GistPageSetNonLeaf(page)	( GistPageGetOpaque(page)->flags &= ~F_LEAF)
 
 #define GistPageIsDeleted(page) ( GistPageGetOpaque(page)->flags & F_DELETED)
 #define GistPageSetDeleted(page)	( GistPageGetOpaque(page)->flags |= F_DELETED)