Fix node-gyp configuration for example 'exception'.

Examples/javascript/exception/binding.gyp

@@ -2,7 +2,28 @@
   "targets": [
     {
       "target_name": "example",
-      "sources": [ "example.cxx", "example_wrap.cxx" ]
+      "sources": [ "example.cxx", "example_wrap.cxx" ],
+      'defines': [
+        'BUILDING_NODE_EXTENSION=1',
+      ],
+      'conditions': [
+        ['OS=="mac"',
+          {
+            'xcode_settings': {
+              'GCC_ENABLE_CPP_RTTI': 'YES',
+              'GCC_ENABLE_CPP_EXCEPTIONS' : 'YES'
+            }
+          }
+        ],
+        ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris"',
+          {
+            'cflags': [ "-Wno-unused-variable", "-Wno-unused-but-set-variable", "-Wno-unused-but-set-parameter"],
+            'cflags_cc': [ "-Wno-unused-variable", "-Wno-unused-but-set-variable", "-Wno-unused-but-set-parameter"],
+            'cflags!': [ '-fno-exceptions' ],
+            'cflags_cc!': [ '-fno-exceptions', '-fno-rtti' ]
+          }
+        ]
+      ]
     }
   ]
 }