Fix Python compile errors with overloading and varargs

Fixes wrapping overloaded functions/constructors where a vararg
function is declared after a non-vararg function.
This is a long standing bug in the Python layer exposed since fastunpack
was turned on by default.

Examples/test-suite/go/varargs_overload_runme.go

@@ -35,4 +35,40 @@ func main() {
 	if varargs_overload.Vararg_over4("Hello", 123) != "Hello" {
 		panic(8)
 	}
+
+
+        // Same as above but non-vararg function declared first
+
+	if varargs_overload.Vararg_over6("Hello") != "Hello" {
+		panic(0)
+	}
+	if varargs_overload.Vararg_over6(2) != "2" {
+		panic(1)
+	}
+
+	if varargs_overload.Vararg_over7("Hello") != "Hello" {
+		panic(2)
+	}
+	if varargs_overload.Vararg_over7(2, 2.2) != "2 2.2" {
+		panic(3)
+	}
+
+	if varargs_overload.Vararg_over8("Hello") != "Hello" {
+		panic(4)
+	}
+	if varargs_overload.Vararg_over8(2, 2.2, "hey") != "2 2.2 hey" {
+		panic(5)
+	}
+
+	if varargs_overload.Vararg_over9("Hello") != "Hello" {
+		panic(6)
+	}
+
+	if varargs_overload.Vararg_over9(123) != "123" {
+		panic(7)
+	}
+
+	if varargs_overload.Vararg_over9("Hello", 123) != "Hello" {
+		panic(8)
+	}
 }