Add failing test for redefined types

Author: owen-mc

go/ql/test/library-tests/semmle/go/dataflow/ExternalFlowInheritance/test_fields.go

@@ -83,3 +83,13 @@ func TestFieldsSEmbedS1AndSEmbedS1(t test.SEmbedS1AndSEmbedS1) {
 	a := t.SourceField
 	t.SinkField = a // $ S1[t] ql_S1
 }
+
+func TestFieldsRedefinedP1(t test.RedefinedP1) {
+	a := t.SourceField
+	t.SinkField = a // $ P1[f] P1[t] ql_P1
+}
+
+func TestFieldsRedefinedS1(t test.RedefinedS1) {
+	a := t.SourceField
+	t.SinkField = a // $ ql_S1 MISSING: S1[f] S1[t]
+}

go/ql/test/library-tests/semmle/go/dataflow/ExternalFlowInheritance/test_methods.go

@@ -171,3 +171,9 @@ func TestMethodsSEmbedS1AndSEmbedS1(t test.SEmbedS1AndSEmbedS1) {
 	y := t.Step(x)
 	t.Sink(y) // $ I1[t] S1[t] ql_S1
 }
+
+func TestMethodsRedefinedI1(t test.RedefinedI1) {
+	x := t.Source()
+	y := t.Step(x)
+	t.Sink(y) // $ ql_I1 MISSING: I1[f] I1[t] SPURIOUS: ql_P1 ql_S1
+}