tools: Use `throw new Error()` consistently

In preparation for a lint rule that will enforce `throw new Error()`
over `throw Error()`, fix the handful of instances in the code that
use `throw Error()`.

PR-URL: https://github.com/nodejs/node/pull/3714
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/test/parallel/test-http-mutable-headers.js b/test/parallel/test-http-mutable-headers.js
index 2a60117328..af8fd6d7e8 100644
--- a/test/parallel/test-http-mutable-headers.js
+++ b/test/parallel/test-http-mutable-headers.js
@@ -110,7 +110,7 @@ function nextTest() {
         break;
 
       default:
-        throw Error('?');
+        throw new Error('?');
     }
 
     response.setEncoding('utf8');