Swift: Add test case.

Author: geoffw0

swift/ql/test/query-tests/Security/CWE-311/SensitiveExprs.expected

@@ -138,6 +138,7 @@
 | testGRDB.swift:208:81:208:81 | password | label:password, type:credential |
 | testGRDB.swift:210:85:210:85 | password | label:password, type:credential |
 | testGRDB.swift:212:99:212:99 | password | label:password, type:credential |
+| testRealm2.swift:18:11:18:11 | myPassword | label:myPassword, type:credential |
 | testRealm.swift:31:20:31:20 | .password | label:password, type:credential |
 | testRealm.swift:41:11:41:11 | myPassword | label:myPassword, type:credential |
 | testRealm.swift:49:11:49:11 | myPassword | label:myPassword, type:credential |

swift/ql/test/query-tests/Security/CWE-311/testRealm2.swift

@@ -0,0 +1,21 @@
+//codeql-extractor-options: -module-name RealmSwift
+
+// --- stubs ---
+
+class Object {
+}
+
+// --- tests ---
+
+class MyRealmSwiftObject3 : Object {
+	override init() { data = "" }
+
+	var data: String
+}
+
+func test1(o: MyRealmSwiftObject3, myHarmless: String, myPassword : String) {
+	// ...
+	o.data = myPassword // BAD [NOT DETECTED]
+	o.data = myHarmless
+	// ...
+}