Restore -rdynamic in Product mode build

runtime/bin/BUILD.gn

 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 import("gypi_contents.gni")
 import("../runtime_args.gni")
 import("../../build/compiled_action.gni")
 
 declare_args() {
   # Controls the kind of core snapshot linked into the standalone VM. Using a
@@ skipping 642 matching lines @@
               ] + extra_sources
 
     include_dirs = [
       "..",
       "//third_party",
     ]
 
     if (is_win) {
       ldflags = [ "/EXPORT:Dart_True" ]
     } else {
-      if (dart_runtime_mode != "release") {
-        ldflags = [ "-rdynamic" ]
-      }
+      # Adds all symbols to the dynamic symbol table, not just used ones.
+      # This is needed to make native extensions work.
+      ldflags = [ "-rdynamic" ]
     }
 
     if (is_win) {
       libs = [
         "iphlpapi.lib",
         "psapi.lib",
         "ws2_32.lib",
         "Rpcrt4.lib",
         "winmm.lib",
       ]
@@ skipping 277 matching lines @@
   ]
   if (is_linux || is_android) {
     cflags = [ "-fPIC" ]
   }
   if (is_win) {
     libs = [ "dart.lib" ]
     abs_root_out_dir = rebase_path(root_out_dir)
     ldflags = [ "/LIBPATH:$abs_root_out_dir" ]
   }
 }