node: emit 'exit' when exiting with error

Fix nodejs#3555

src/node.js

@@ -251,6 +251,14 @@
         caught = process.emit('uncaughtException', er);
       }
       // if someone handled it, then great.  otherwise, die in C++ land
+      // since that means that we'll exit the process, emit the 'exit' event
+      if (!caught) {
+        try {
+          process.emit('exit', 1);
+        } catch (er) {
+          // nothing to be done about it at this point.
+        }
+      }
       return caught;
     };
   };

test/message/error_exit.js

@@ -0,0 +1,29 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var common = require('../common.js');
+var assert = require('assert');
+
+process.on('exit', function(code) {
+  console.error('Exiting with code=%d', code);
+});
+
+assert.equal(1, 2);

test/message/error_exit.out

@@ -0,0 +1,13 @@
+Exiting with code=1
+
+assert.js:*
+  throw new assert.AssertionError({
+        ^
+AssertionError: 1 == 2
+    at Object.<anonymous> (*test*message*error_exit.js:*:*)
+    at Module._compile (module.js:*:*)
+    at Object.Module._extensions..js (module.js:*:*)
+    at Module.load (module.js:*:*)
+    at Function.Module._load (module.js:*:*)
+    at Module.runMain (module.js:*:*)
+    at process._tickCallback (node.js:*:*)

test/message/undefined_reference_in_new_context.js

@@ -30,7 +30,7 @@ common.error('before');
 var Script = process.binding('evals').NodeScript;
 
 // undefined reference
-script = new Script('foo.bar = 5;');
+var script = new Script('foo.bar = 5;');
 script.runInNewContext();
 
 common.error('after');