Add two new types to Generator.Bind

GLeglClientBufferEXT, and GLVULKANPROCNV. Both are mapped to IntPtrs.

src/Generator.Bind/Specifications/csharp.tm

@@ -111,6 +111,14 @@ GLfixed, int
 GLeglImageOES, IntPtr
 
 
+# External egl buffer type added in OpenGL 4.6
+GLeglClientBufferEXT, IntPtr
+
+
+# nVidia vulkan entry point, added by NV_draw_vulkan_image extension
+GLVULKANPROCNV, IntPtr
+
+
 # OpenCL types.
 _cl_context, IntPtr
 _cl_event, IntPtr