Fix concurrent cache map race in fillInIDs lock planning

Build query dependency trees before collecting cache locks so fillInIDs holds read locks for all resources it may traverse, preventing concurrent map read/write panics under stress.

Author: adkerr

core/concurrent_cache/concurrent_cache.go

@@ -402,19 +402,16 @@ func assembleQueries(queries [][]Subquery) (roots [][]int, cachesPresent map[res
 		if err != nil {
 			return nil, nil, false, false, err
 		}
-		for _, sq := range q {
+		queries[i], roots[i] = buildTrees(ri, q)
+		for _, sq := range queries[i] {
 			if sq.newKey != "" {
 				hasNewKeys = true
 			}
+			cachesPresent[sq.res] = struct{}{}
 			if sq.op != list && sq.op != inconsistentRead {
 				hasConsistentLocks = true
 			}
 		}
-		queries[i], roots[i] = buildTrees(ri, q)
-		// Include synthetic read dependencies added by buildTree so fillInIDs holds cache RLocks.
-		for _, sq := range queries[i] {
-			cachesPresent[sq.res] = struct{}{}
-		}
 	}
 
 	return roots, cachesPresent, hasConsistentLocks, hasNewKeys, nil