Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

PR #15822 fixed the warning for direct hyphenated gem requires like
`benchmark/ips` → `benchmark-ips`. However, hyphenated gems often
provide multiple files under their namespace.

For example, `benchmark-ips` provides:
- benchmark/ips.rb
- benchmark/timing.rb
- benchmark/compare.rb

When requiring `benchmark/timing`, the previous fix only checked for
`benchmark-timing` gem (doesn't exist), not `benchmark-ips` which
actually provides the file.

This fix checks if ANY gem matching `{prefix}-*` is in the bundle
specs, which covers all subfeatures provided by hyphenated gems.

Reported in https://github.com/ruby/ruby/pull/15822#issuecomment-123456

When requiring a file like "benchmark/ips", the warning system would
incorrectly warn about the "benchmark" gem not being a default gem,
even when the user has "benchmark-ips" (a separate third-party gem)
in their Gemfile.

The fix checks if a hyphenated version of the require path exists in
the bundle specs before issuing a warning. For example, requiring
"benchmark/ips" now checks for both "benchmark" and "benchmark-ips"
in the Gemfile.

[Bug #21828]

[Bug #20641] `Gem::BUNDLED_GEMS.warning?` adds a lot of extra
work on top of `require`. When the call end up atually loading code
the overhead is somewhat marginal.

However it's not uncommon for code to go some late `require` in some
paths, so it's expected that calling `require` with something already
required is somewhat fast, and `bundled_gems.rb` breaks this assumption.

To avoid this, we can have a fast path that in most case allow to
short-circuit all the heavy computations. If we extract the feature
basename and it doesn't match any of the bundled gems we care about
we can return very early.

With this change `require 'date'` is now only 1.33x slower on Ruby
3.3.3, than it was on Ruby 3.2.2, whereas before this change it
was at least 100x slower.