stdlib: change crypt() function used by pw_hash

Basic Info
Module Version: 8.1.0
Puppet Version: 7.x
OS Name/Version: CentOS 8.x

Describe your issue in as much detail as possible...

Desired Behavior: pw_hash() can be used in heavily loaded Puppet masters

Actual Behavior: Puppet master workers crash with backtraces in libcrypt

Seems that CentOS 8 + JRuby's String#crypt are not thread-safe. (See https://tickets.puppetlabs.com/browse/SERVER-2862 for example)

Please provide a way of choosing the crypt() implementation used in pw_hash() or maybe just not use the JRuby-provided method.

Currently as a workaround we patch the stdlib module locally so that it always uses the Apache Commons Codec

I have attached a small test script that crashes with CentOS 8.x + JRuby (tested latest 9.2 and 9.3)

Does not crash with CentOS 8.x and bundled Ruby, does not crash with CentOS 7.x and JRuby