Revert "Revert "Add RTLD_NODELETE flag support""

This reverts commit 69c5d108a5cb44167a04d42ffdad6a39648ed235.
diff --git a/libc/include/dlfcn.h b/libc/include/dlfcn.h
index 8dde08c..afa7687 100644
--- a/libc/include/dlfcn.h
+++ b/libc/include/dlfcn.h
@@ -64,6 +64,7 @@
   RTLD_GLOBAL = 2,
 #endif
   RTLD_NOLOAD = 4,
+  RTLD_NODELETE = 0x01000,
 };
 
 #if defined (__LP64__)