dlfcn-util: add DLSYM_ARG() helper

src/basic/dlfcn-util.h

@@ -8,3 +8,9 @@
 DEFINE_TRIVIAL_CLEANUP_FUNC(void*, dlclose);
 
 int dlsym_many_and_warn(void *dl, int level, ...);
+
+/* Macro useful for putting together variable/symbol name pairs when calling dlsym_many_and_warn(). Assumes
+ * that each library symbol to resolve will be placed in a variable with the "sym_" prefix, i.e. a symbol
+ * "foobar" is loaded into a variable "sym_foobar". */
+#define DLSYM_ARG(arg) \
+        &sym_##arg, STRINGIFY(arg)