Fix typalign in rangetypes statistics

6df7a969 introduces multirange types, whose typanalyze function shares
infrastructure with range types typanalyze function.  Since 6df7a969,
information about type gathered by statistics is filled from typcache.
But typalign is mistakenly always set to double.  This commit fixes this
oversight.

src/backend/utils/adt/rangetypes_typanalyze.c

@@ -330,7 +330,7 @@ compute_range_stats(VacAttrStats *stats, AnalyzeAttrFetchFunc fetchfunc,
 			stats->statypid[slot_idx] = typcache->type_id;
 			stats->statyplen[slot_idx] = typcache->typlen;
 			stats->statypbyval[slot_idx] = typcache->typbyval;
-			stats->statypalign[slot_idx] = 'd';
+			stats->statypalign[slot_idx] =  typcache->typalign;
 
 			slot_idx++;
 		}