Do not skip call to MarkBufferDirtyHint for temp tables.

In markDirty() seems oversight in commit
8c8b5c39 to avoid calling MarkBufferDirtyHint()
for temp tables. Previous patch used relation->rd_istemp before calling
XLogSaveBufferForHint() in MarkBufferDirtyHint() that was unnecessary given it
already checks for BM_PERMANENT. So, call now MarkBufferDirtyHint()
unconditionally.

src/backend/utils/time/tqual.c

@@ -91,9 +91,11 @@ markDirty(Buffer buffer, Relation relation, HeapTupleHeader tuple, bool isXmin)
 
 	if (!gp_disable_tuple_hints)
 	{
-		/* GPDB_91_MERGE_FIXME: what is the rationale of not dirtying local buffers? */
-		if (relation->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
-			MarkBufferDirtyHint(buffer);
+		/*
+		 * Based on BM_PERMANENT it decides if should xlog for temp tables or
+		 * not. So, can safely call it for any buffer.
+		 */
+		MarkBufferDirtyHint(buffer);
 		return;
 	}