Add failing tests highlighting missing models

Author: owen-mc

go/ql/test/library-tests/semmle/go/dataflow/ExternalValueFlow/test.go

@@ -208,6 +208,9 @@ func simpleflow() {
 
 	temp := test.SourceVariable
 	test.SinkVariable = temp // $ hasValueFlow="temp"
+
+	b.Sink1(new(src))  // $ hasValueFlow="call to new"
+	b.Sink1(*new(src)) // $ hasValueFlow="dereference"
 }
 
 func srcParam(src string, b test.B) {

go/ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/Builtin.go

@@ -60,6 +60,13 @@ func TaintStepTest_Min(sourceCQL interface{}) interface{} {
 	return intoInterface
 }
 
+func TaintStepTest_New(sourceCQL interface{}) interface{} {
+	from := sourceCQL.(int)
+	var intoInterface *int
+	intoInterface = new(from)
+	return *intoInterface
+}
+
 func RunAllTaints_Builtin() {
 	{
 		source := newSource(0)
@@ -101,4 +108,9 @@ func RunAllTaints_Builtin() {
 		out := TaintStepTest_Min(source)
 		sink(4, out)
 	}
+	{
+		source := newSource(5)
+		out := TaintStepTest_New(source)
+		sink(5, out)
+	}
 }