Add missing POSIX 2024 tests.

I'd already done some (such as qsort_r()), but hadn't systematically gone through the additions.

Change-Id: Ia8e848f2554c0096b6e399e13b88bee03cb9eb84
diff --git a/tests/headers/posix/dlfcn_h.c b/tests/headers/posix/dlfcn_h.c
index 4800075..e8dc648 100644
--- a/tests/headers/posix/dlfcn_h.c
+++ b/tests/headers/posix/dlfcn_h.c
@@ -36,6 +36,17 @@
   MACRO(RTLD_GLOBAL);
   MACRO(RTLD_LOCAL);
 
+#if !defined(__GLIBC__)  // Our glibc is too old.
+  TYPE(Dl_info);
+  STRUCT_MEMBER(Dl_info, const char*, dli_fname);
+  STRUCT_MEMBER(Dl_info, void*, dli_fbase);
+  STRUCT_MEMBER(Dl_info, const char*, dli_sname);
+  STRUCT_MEMBER(Dl_info, void*, dli_saddr);
+#endif
+
+#if !defined(__GLIBC__)  // Our glibc is too old.
+  FUNCTION(dladdr, int (*f)(const void*, Dl_info*));
+#endif
   FUNCTION(dlclose, int (*f)(void*));
   FUNCTION(dlerror, char* (*f)(void));
   FUNCTION(dlopen, void* (*f)(const char*, int));