add posix library loading functions

src/lib/posix/module.c

@@ -6,4 +6,15 @@
 void *tc_dlopen(const char *path) {
     return dlopen(path, RTLD_LAZY);
 }
-        
+
+void *tc_dlsym(void *handle, const char *name) {
+    return dlsym(handle, name);
+}
+
+void tc_dlclose(void *handle) {
+    dlclose(handle);
+}
+
+char *tc_dlerror() {
+    return dlerror();
+}