Add test for fake function pointers

Author: facchinm

src/arduino.cc/builder/test/sketch_with_fake_function_pointer/sketch_with_fake_function_pointer.ino

@@ -0,0 +1,19 @@
+template< uint16_t nBuffSize >
+  class Foo{
+    public: 
+  
+    template< uint16_t N >
+      Foo &operator +=( const Foo<N> &ref ){
+        //...
+        return *this;
+    }
+};
+
+Foo<64> a;
+Foo<32> b;
+
+void setup(){
+  a += b;
+}
+
+void loop(){}

src/arduino.cc/builder/test/try_build_of_problematic_sketch_test.go

@@ -205,6 +205,10 @@ func TestTryBuild039(t *testing.T) {
 	tryBuildWithContext(t, ctx, "sketch12", "sketch12.ino")
 }
 
+func TestTryBuild040(t *testing.T) {
+	tryBuild(t, "sketch_with_fake_function_pointer", "sketch_with_fake_function_pointer.ino")
+}
+
 func makeDefaultContext(t *testing.T) *types.Context {
 	DownloadCoresAndToolsAndLibraries(t)