Use libdl to get symbols for backtraces

tools/gyp/v8.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 1352 matching lines @@
         ['want_separate_host_toolset==1', {
           'toolsets': ['host', 'target'],
         }, {
           'toolsets': ['target'],
         }],
         ['OS=="linux"', {
             'conditions': [
               ['nacl_target_arch=="none"', {
                 'link_settings': {
                   'libraries': [
+                    '-ldl',
                     '-lrt'
                   ],
                 },
               }, {
                 'defines': [
                   'V8_LIBRT_NOT_AVAILABLE=1',
                 ],
               }],
             ],
             'sources': [
               '../../src/base/platform/platform-linux.cc',
               '../../src/base/platform/platform-posix.cc'
             ],
           }
         ],
         ['OS=="android"', {
             'sources': [
               '../../src/base/platform/platform-posix.cc'
             ],
+            'link_settings': {
+              'libraries': [
+                '-ldl'
+              ]
+            },
             'conditions': [
               ['host_os=="mac"', {
                 'target_conditions': [
                   ['_toolset=="host"', {
                     'sources': [
                       '../../src/base/platform/platform-macos.cc'
                     ]
                   }, {
                     'sources': [
                       '../../src/base/platform/platform-linux.cc'
@@ skipping 418 matching lines @@
         }],
         ['want_separate_host_toolset==1', {
           'toolsets': ['host'],
         }, {
           'toolsets': ['target'],
         }],
       ],
     },
   ],
 }