Add godot-sandbox as a module.

godot/modules/sandbox/SCsub

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+from misc.utility.scons_hints import *
+
+Import("env")
+Import("env_modules")
+
+def get_sufix():
+    suffix = ".{}.{}".format(env["platform"], env["target"])
+    # In godot it's "linuxbsd"
+    suffix = suffix.replace("linuxbsd", "linux")
+    # Only take release
+    suffix = suffix.replace("editor", "template_release")
+    suffix = suffix.replace("template_debug", "template_release")
+    if env.dev_build:
+        suffix += ".dev"
+    if env["precision"] == "double":
+        suffix += ".double"
+    suffix += "." + env["arch"]
+    if not env["threads"]:
+        suffix += ".nothreads"
+    return suffix.replace("editor", "template_release")
+
+# Libraries
+if env["platform"] == "macos" or env["platform"] == "ios":
+    base_path = "#modules/sandbox/bin/addons/godot_sandbox/bin/libgodot_riscv{}.framework".format(get_sufix())
+    base_file = "libgodot_riscv{}".format(get_sufix())
+else:
+    base_path = "#modules/sandbox/bin/addons/godot_sandbox/bin"
+    base_file = "libgodot_riscv{}".format(get_sufix())
+
+env.Append(LIBS=[base_file])
+env.Append(LIBPATH=[base_path])
+
+# Godot-cpp
+base_path = "#modules/sandbox/ext/godot-cpp/bin"
+base_file = "libgodot-cpp{}".format(get_sufix())
+
+env.Append(LIBS=[base_file])
+env.Append(LIBPATH=[base_path])
+
+# Sources
+env_gdextension = env_modules.Clone()
+
+env_gdextension.add_source_files(env.modules_sources, "*.cpp")