Found this oddity when benchmarking Leyden. Current mainline is behind JDK 17, 21 on basic Leyden reproducer. I bisected the major source of this regression to JDK-8294960.

Here:

```
% cat HelloStream.java
import java.util.*;
import java.util.stream.*;

public class HelloStream {
    public static void main(String ... args) {
        var words = List.of("hello", "fuzzy", "world");
        var greeting = words.stream()
            .filter(w -> !w.contains("z"))
            .collect(Collectors.joining(", "));
        System.out.println(greeting);  // hello, world
    }
}

% rm -f *.class *.jar
% $J/bin/javac HelloStream.java
% $J/bin/jar cf hellostream.jar *.class

% hyperfine -w 50 -r 100 '$J/bin/java -Xmx256m -XX:+UseSerialGC -cp hellostream.jar HelloStream'
```

jdk-24+0: 38.8 ms ±   0.4 ms
Before JDK-8294960: 38.4 ms ± 0.7 ms
At JDK-8294960: 41.8 ms ± 0.5 ms
current mainline:41.0 ms ± 0.4 ms 

Mainline improved a bit after, I think, but it looks that JDK-8294960 is the major contributor for regression.