vm: add error message if we abort

Add an error message in watchdog if we abort because uv_loop_init fails.

PR-URL: nodejs#8634
Fixes: nodejs#8555
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ilkka Myller <ilkka.myller@nodefield.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

Author: fhinkel

src/node_watchdog.cc

@@ -13,7 +13,10 @@ Watchdog::Watchdog(v8::Isolate* isolate, uint64_t ms) : isolate_(isolate),
   loop_ = new uv_loop_t;
   CHECK(loop_);
   rc = uv_loop_init(loop_);
-  CHECK_EQ(0, rc);
+  if (rc != 0) {
+    FatalError("node::Watchdog::Watchdog()",
+               "Failed to initialize uv loop.");
+  }
 
   rc = uv_async_init(loop_, &async_, &Watchdog::Async);
   CHECK_EQ(0, rc);