Add static Vulkan loader.

Initial Vulkan support for Windows.
Initial Vulkan support for macOS.

modules/gdnative/arvr/arvr_interface_gdnative.cpp

@@ -286,7 +286,9 @@ void GDAPI godot_arvr_blit(godot_int p_eye, godot_rid *p_render_target, godot_re
 		screen_rect.size.x /= 2.0;
 		screen_rect.position.x += screen_rect.size.x;
 	}
+#ifndef _MSC_VER
 #warning this needs to be redone
+#endif
 #if 0
 	VSG::rasterizer->blit_render_target_to_screen(*render_target, screen_rect, 0);
 #endif
@@ -298,7 +300,9 @@ godot_int GDAPI godot_arvr_get_texid(godot_rid *p_render_target) {
 	RID *render_target = (RID *)p_render_target;
 
 	RID eye_texture = VSG::storage->render_target_get_texture(*render_target);
+#ifndef _MSC_VER
 #warning need to obtain this ID again
+#endif
 	uint32_t texid = 0; //VS::get_singleton()->texture_get_texid(eye_texture);
 
 	return texid;