QL: add failing callgraph test

Author: erik-krogh

ql/test/callgraph/Bar.qll

@@ -0,0 +1,9 @@
+import ql
+
+module Firebase {
+  module Database {
+    query predicate ref(int i) { i = snapshot() }
+  }
+
+  int snapshot() { result = 2 }
+}

ql/test/printAst/printAst.expected

@@ -288,6 +288,10 @@ edges
 | Foo.qll:6:23:6:36 | ComparisonFormula | Foo.qll:6:30:6:30 | ComparisonOp | semmle.order | 14 |
 | Foo.qll:6:23:6:36 | ComparisonFormula | Foo.qll:6:32:6:36 | String | semmle.label | getRightOperand() |
 | Foo.qll:6:23:6:36 | ComparisonFormula | Foo.qll:6:32:6:36 | String | semmle.order | 15 |
+| Foo.qll:9:1:9:5 | annotation | Foo.qll:9:1:9:5 | annotation | semmle.label | getAnAnnotation() |
+| Foo.qll:9:1:9:5 | annotation | Foo.qll:9:1:9:5 | annotation | semmle.order | 16 |
+| Foo.qll:9:7:11:1 | ClasslessPredicate foo | Foo.qll:9:1:9:5 | annotation | semmle.label | getAnAnnotation() |
+| Foo.qll:9:7:11:1 | ClasslessPredicate foo | Foo.qll:9:1:9:5 | annotation | semmle.order | 16 |
 | Foo.qll:9:7:11:1 | ClasslessPredicate foo | Foo.qll:9:21:9:25 | f | semmle.label | getParameter(_) |
 | Foo.qll:9:7:11:1 | ClasslessPredicate foo | Foo.qll:9:21:9:25 | f | semmle.order | 18 |
 | Foo.qll:9:7:11:1 | ClasslessPredicate foo | Foo.qll:10:3:10:85 | ComparisonFormula | semmle.label | getBody() |