Rebased from Fedora rawhide, commit: 6b2ff68.
* Except "Fix FTBFS due to an incompatible load" as that is included as
a separate commit to highlight the change.
* Add missing `rubygem-` prefix for bundled provide of 'connection_pool'.
* Pass ldflags to gem install via CONFIGURE_ARGS
* Remove IRB dependency from rubygem-rdoc.
* Fix flaky excon test suite.
* Properly support DWARF5 debug information.
Related: rhbz#1920533
* Bundle OpenSSL into StdLib.
* Fix SEGFAULT in rubygem-shoulda-matchers test suite.
* Provide `gem.build_complete` file for binary gems.
* Re-enable test suite.
* ruby-default-gems have to depend on rubygem(io-console) due to
reline.
* Fix SEGFAULT preventing rubygem-unicode to build on armv7hl.
* Add support for reworked RubyGems plugins.
* Use proper path for plugin wrappers.
* Extract RSS and REXML into separate subpackages, because they were
moved from default gems to bundled gems.
* Drop Net::Telnet and XMLRPC packages, because they were dropped from
Ruby.
Resolves: rhbz#1938942
