Add missing `gb_internal`

src/build_settings.cpp

@@ -720,7 +720,7 @@ gb_internal String internal_odin_root_dir(void) {
 
 #include <mach-o/dyld.h>
 
-String path_to_fullpath(gbAllocator a, String s);
+gb_internal String path_to_fullpath(gbAllocator a, String s);
 
 gb_internal String internal_odin_root_dir(void) {
 	String path = global_module_path;