Clean up some code using "(expr) ? true : false"

All the code paths simplified here were already using a boolean or used
an expression that led to zero or one, making the extra bits
unnecessary.

Author: Justin Pryzby
Reviewed-by: Tom Lane, Michael Paquier, Peter Smith
Discussion: https://postgr.es/m/20210428182936.GE27406@telsasoft.com

src/backend/access/gin/gindatapage.c

@@ -241,7 +241,7 @@ dataIsMoveRight(GinBtree btree, Page page)
 	if (GinPageIsDeleted(page))
 		return true;
 
-	return (ginCompareItemPointers(&btree->itemptr, iptr) > 0) ? true : false;
+	return (ginCompareItemPointers(&btree->itemptr, iptr) > 0);
 }
 
 /*

src/backend/access/gin/ginutil.c

@@ -100,7 +100,7 @@ initGinState(GinState *state, Relation index)
 	MemSet(state, 0, sizeof(GinState));
 
 	state->index = index;
-	state->oneCol = (origTupdesc->natts == 1) ? true : false;
+	state->oneCol = (origTupdesc->natts == 1);
 	state->origTupdesc = origTupdesc;
 
 	for (i = 0; i < origTupdesc->natts; i++)

src/backend/access/gist/gistsplit.c

@@ -303,9 +303,9 @@ supportSecondarySplit(Relation r, GISTSTATE *giststate, int attno,
 		penalty2 = gistpenalty(giststate, attno, entry1, false, &entrySR, false);
 
 		if (penalty1 < penalty2)
-			leaveOnLeft = (sv->spl_ldatum_exists) ? true : false;
+			leaveOnLeft = sv->spl_ldatum_exists;
 		else
-			leaveOnLeft = (sv->spl_rdatum_exists) ? true : false;
+			leaveOnLeft = sv->spl_rdatum_exists;
 	}
 
 	if (leaveOnLeft == false)

src/backend/access/hash/hash.c

@@ -816,7 +816,7 @@ hashbucketcleanup(Relation rel, Bucket cur_bucket, Buffer bucket_buf,
 				XLogRecPtr	recptr;
 
 				xlrec.clear_dead_marking = clear_dead_marking;
-				xlrec.is_primary_bucket_page = (buf == bucket_buf) ? true : false;
+				xlrec.is_primary_bucket_page = (buf == bucket_buf);
 
 				XLogBeginInsert();
 				XLogRegisterData((char *) &xlrec, SizeOfHashDelete);

src/backend/access/hash/hashinsert.c

@@ -176,7 +176,7 @@ restart_insert:
 			LockBuffer(buf, BUFFER_LOCK_UNLOCK);
 
 			/* chain to a new overflow page */
-			buf = _hash_addovflpage(rel, metabuf, buf, (buf == bucket_buf) ? true : false);
+			buf = _hash_addovflpage(rel, metabuf, buf, (buf == bucket_buf));
 			page = BufferGetPage(buf);
 
 			/* should fit now, given test above */

src/backend/access/hash/hashovfl.c

@@ -953,7 +953,7 @@ readpage:
 						xl_hash_move_page_contents xlrec;
 
 						xlrec.ntups = nitups;
-						xlrec.is_prim_bucket_same_wrt = (wbuf == bucket_buf) ? true : false;
+						xlrec.is_prim_bucket_same_wrt = (wbuf == bucket_buf);
 
 						XLogBeginInsert();
 						XLogRegisterData((char *) &xlrec, SizeOfHashMovePageContents);

src/backend/access/hash/hashpage.c

@@ -1195,7 +1195,7 @@ _hash_splitbucket(Relation rel,
 					all_tups_size = 0;
 
 					/* chain to a new overflow page */
-					nbuf = _hash_addovflpage(rel, metabuf, nbuf, (nbuf == bucket_nbuf) ? true : false);
+					nbuf = _hash_addovflpage(rel, metabuf, nbuf, (nbuf == bucket_nbuf));
 					npage = BufferGetPage(nbuf);
 					nopaque = (HashPageOpaque) PageGetSpecialPointer(npage);
 				}

src/backend/access/heap/heapam_visibility.c

@@ -1475,7 +1475,7 @@ HeapTupleIsSurelyDead(HeapTuple htup, GlobalVisState *vistest)
 	 * all relevant hint bits were just set moments ago).
 	 */
 	if (!HeapTupleHeaderXminCommitted(tuple))
-		return HeapTupleHeaderXminInvalid(tuple) ? true : false;
+		return HeapTupleHeaderXminInvalid(tuple);
 
 	/*
 	 * If the inserting transaction committed, but any deleting transaction