[ox/std] Move most macros to def.hpp in anticipation of C++20 modules

deps/ox/src/ox/std/CMakeLists.txt

@@ -24,7 +24,6 @@ add_library(
 		buffer.cpp
 		buildinfo.cpp
 		byteswap.cpp
-		defer.hpp
 		fmt.cpp
 		heapmgr.cpp
 		memops.cpp
@@ -71,7 +70,9 @@ install(
 		buffer.hpp
 		buildinfo.hpp
 		byteswap.hpp
+		def.hpp
 		defines.hpp
+		defer.hpp
 		error.hpp
 		fmt.hpp
 		hardware.hpp