Ruby

merge revision(s) a3eb5e5c70eaee12964cdd807b8f19950003141f: [Backport #20573]

    Don't call `Warning.warn` unless the category is enabled (#10981)

    Don't call `Warning.warn` unless the category is enabled

    The warning category should be enabled if we want to call
    `Warning.warn`.

    This commit speeds up the following benchmark:

    ```ruby
    eval "def test; " +
      1000.times.map { "'  '.chomp!" }.join(";") + "; end"

    def run_benchmark count
      i = 0
      while i < count
        start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
        yield
        ms = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
        puts "itr ##{i}: #{(ms * 1000).to_i}ms"
        i += 1
      end
    end

    run_benchmark(25) do
      250.times do
        test
      end
    end
    ```

    On `master` this runs at about 92ms per iteration. With this patch, it
    is 7ms per iteration.

    [Bug #20573]