lib,test: use regular expression literals

Replace RegExp constructors with regular expression literals where
possible.

PR-URL: https://github.com/nodejs/node/pull/12807
Backport-PR-URL: https://github.com/nodejs/node/pull/13776
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

test/parallel/test-buffer-alloc.js

@@ -984,8 +984,8 @@ Buffer.poolSize = ps;
 assert.throws(() => Buffer.allocUnsafe(10).copy(),
               /TypeError: argument should be a Buffer/);
 
-const regErrorMsg = new RegExp('First argument must be a string, Buffer, ' +
-                               'ArrayBuffer, Array, or array-like object.');
+const regErrorMsg =
+  /First argument must be a string, Buffer, ArrayBuffer, Array, or array-like object\./;
 
 assert.throws(() => Buffer.from(), regErrorMsg);
 assert.throws(() => Buffer.from(null), regErrorMsg);

test/parallel/test-tls-env-bad-extra-ca.js

@@ -33,10 +33,9 @@ fork(__filename, opts)
     assert.strictEqual(status, 0, 'client did not succeed in connecting');
   }))
   .on('close', common.mustCall(function() {
-    assert(stderr.match(new RegExp(
-      'Warning: Ignoring extra certs from.*no-such-file-exists' +
-      '.* load failed:.*No such file or directory'
-    )), stderr);
+    assert(stderr.match(
+      /Warning: Ignoring extra certs from.*no-such-file-exists.* load failed:.*No such file or directory/
+    ), stderr);
   }))
   .stderr.setEncoding('utf8').on('data', function(str) {
     stderr += str;

test/parallel/test-tls-key-mismatch.js

@@ -8,8 +8,8 @@ if (!common.hasCrypto) {
 const assert = require('assert');
 const tls = require('tls');
 const fs = require('fs');
-const errorMessageRegex = new RegExp('^Error: error:0B080074:x509 ' +
-  'certificate routines:X509_check_private_key:key values mismatch$');
+const errorMessageRegex =
+  /^Error: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch$/;
 
 const options = {
   key: fs.readFileSync(common.fixturesDir + '/keys/agent1-key.pem'),

test/parallel/test-util-inherits.js

@@ -4,8 +4,7 @@ require('../common');
 const assert = require('assert');
 const inherits = require('util').inherits;
 const errCheck =
-  new RegExp('^TypeError: The super constructor to "inherits" must not be ' +
-                      'null or undefined$');
+  /^TypeError: The super constructor to "inherits" must not be null or undefined$/;
 
 
 // super constructor