pch migration to modules [wip]

global_include/interfaces/ITexture_macros.h

@@ -0,0 +1,8 @@
+#pragma once
+
+// Macros cannot cross a module boundary, so they live in a plain header
+// that consumers pull into their global module fragment. The bodies are
+// expanded at the use site, where the imported names are in scope, so this
+// header deliberately includes nothing.
+
+#define null_handle (0)