Improved generator test runner to find tests in embedded setup.

src/Generator.Tests/GeneratorTest.cs

@@ -70,6 +70,11 @@ namespace CppSharp.Utils
             {
                 var path = Path.Combine(directory.FullName, "tests", name);
 
+                if (Directory.Exists(path))
+                    return path;
+
+                path = Path.Combine(directory.FullName, "external", "CppSharp", "tests", name);
+
                 if (Directory.Exists(path))
                     return path;