loader: Reserve space for additional pointers in ast_module_info.

This creates 4 reserved pointers in case we need additional dependency
management fields.

Change-Id: If991ec99b779df1b2dfbd38ce1a0cd79f9e01821

include/asterisk/module.h

@@ -376,6 +376,13 @@ struct ast_module_info {
 	 */
 	const char *enhances;
 
+	/*! These reserved fields should be NULL, they exist to allow addition to this
+	 * structure in a non-breaking way. */
+	void *reserved1;
+	void *reserved2;
+	void *reserved3;
+	void *reserved4;
+
 	/*! The support level for the given module */
 	enum ast_module_support_level support_level;
 };
@@ -448,6 +455,10 @@ void __ast_module_unref(struct ast_module *mod, const char *file, int line, cons
 		NULL,                                                          \
 		NULL,                                                          \
 		NULL,                                                          \
+		NULL,                                                          \
+		NULL,                                                          \
+		NULL,                                                          \
+		NULL,                                                          \
 		support_level,                                                 \
 	};                                                                 \
 	static void  __attribute__((constructor)) __reg_module(void)       \