Added test code.

Author: simonjwright

hello.adb

@@ -0,0 +1,5 @@
+with Ada.Text_IO;
+procedure Hello is
+begin
+   Ada.Text_IO.Put ("hello world from Ada.");
+end Hello;

hello.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main(void) {
+  printf("hello world from C.\n");
+  return 0;
+}

hello.cc

@@ -0,0 +1,6 @@
+#include <iostream>
+int main()
+{
+  std::cout << "hello world from C++.\n";
+  return 0;
+}

hello.f

@@ -0,0 +1,4 @@
+      program hello
+      print *, 'hello world from Fortran.'
+      end
+