add test of buildins

Author: erik-krogh

ql/ql/test/modules/Foo.qll

@@ -19,3 +19,18 @@ import SimpleMod
 private module SecondImpl implements MkThing<MyImpl>::SubMod {
   predicate bar() { none() }
 }
+
+class Node extends int {
+  Node() { this = [0 .. 10] }
+}
+
+predicate sccEdge(Node a, Node b) { a = b % 2 }
+
+private module Scc = QlBuiltins::EquivalenceRelation<Node, sccEdge/2>;
+
+private class TypeFlowScc = Scc::EquivalenceClass;
+
+/** Holds if `n` is part of an SCC of size 2 or more represented by `scc`. */
+predicate sccRepr(Node n, TypeFlowScc scc) { scc = Scc::getEquivalenceClass(n) }
+
+predicate sccJoinStep(Node n, TypeFlowScc scc) { none() }

ql/ql/test/modules/test.expected

@@ -8,6 +8,8 @@ getTarget
 | Foo.qll:19:38:19:52 | MkThing | Foo.qll:9:16:9:22 | MkThing |
 | Foo.qll:19:38:19:60 | TypeExpr | Foo.qll:10:20:10:25 | SubMod |
 | Foo.qll:19:46:19:51 | TypeExpr | Foo.qll:5:16:5:21 | MyImpl |
+| Foo.qll:31:29:31:31 | Scc | Foo.qll:29:16:29:18 | Scc |
+| Foo.qll:34:52:34:54 | Scc | Foo.qll:29:16:29:18 | Scc |
 getTargetType
 | ClassSig.qll:3:23:3:28 | TypeExpr | file://:0:0:0:0 | string |
 | ClassSig.qll:7:12:7:17 | TypeExpr | ClassSig.qll:1:17:1:22 | FooSig |
@@ -23,3 +25,11 @@ getTargetType
 | Foo.qll:19:38:19:52 | MkThing | Foo.qll:9:16:9:22 | MkThing |
 | Foo.qll:19:38:19:60 | TypeExpr | Foo.qll:10:20:10:25 | SubMod |
 | Foo.qll:19:46:19:51 | TypeExpr | Foo.qll:5:16:5:21 | MyImpl |
+| Foo.qll:23:20:23:22 | TypeExpr | file://:0:0:0:0 | int |
+| Foo.qll:27:19:27:22 | TypeExpr | Foo.qll:23:7:23:10 | Node |
+| Foo.qll:27:27:27:30 | TypeExpr | Foo.qll:23:7:23:10 | Node |
+| Foo.qll:29:54:29:57 | TypeExpr | Foo.qll:23:7:23:10 | Node |
+| Foo.qll:31:29:31:31 | Scc | Foo.qll:29:16:29:18 | Scc |
+| Foo.qll:34:19:34:22 | TypeExpr | Foo.qll:23:7:23:10 | Node |
+| Foo.qll:34:52:34:54 | Scc | Foo.qll:29:16:29:18 | Scc |
+| Foo.qll:36:23:36:26 | TypeExpr | Foo.qll:23:7:23:10 | Node |