test: add second argument to assert.throws()

Adds a second argument to the assert.throws() test to implicitly specify
expected error message.

PR-URL: nodejs/node#12016
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>

test/parallel/test-util-inspect-proxy.js

@@ -31,7 +31,8 @@ assert.strictEqual(processUtil.getProxyDetails({}), undefined);
 // and the get function on the handler object defined above
 // is actually invoked.
 assert.throws(
-  () => util.inspect(proxyObj)
+  () => util.inspect(proxyObj),
+  /^Error: Getter should not be called$/
 );
 
 // Yo dawg, I heard you liked Proxy so I put a Proxy