test: add abort test for backtrace validation

This commit adds a test that validates backtraces which are
printed on fatal errors.

PR-URL: https://github.com/nodejs/node/pull/6734
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

test/abort/test-abort-backtrace.js

@@ -0,0 +1,24 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const cp = require('child_process');
+
+if (common.isWindows) {
+  common.skip('Backtraces unimplemented on Windows.');
+  return;
+}
+
+if (process.argv[2] === 'child') {
+  process.abort();
+} else {
+  const child = cp.spawnSync(`${process.execPath}`, [`${__filename}`, 'child']);
+  const frames =
+      child.stderr.toString().trimRight().split('\n').map((s) => s.trim());
+
+  assert.strictEqual(child.stdout.toString(), '');
+  assert.ok(frames.length > 0);
+  // All frames should start with a frame number.
+  assert.ok(frames.every((frame, index) => frame.startsWith(`${index + 1}:`)));
+  // At least some of the frames should include the binary name.
+  assert.ok(frames.some((frame) => frame.includes(`[${process.execPath}]`)));
+}