RFR: 8274412: Add a method to Stream API to consume and close the stream without using try-with-resources

[Tagir F.Valeev]

Currently, when the stream holds a resource, it's necessary to wrap it with try-with-resources. This undermines the compact and fluent style of stream API calls. For example, if we want to get the `List` of files inside the directory and timely close the underlying filehandle, we should use something like this:


List<Path> paths;
try (Stream<Path> stream = Files.list(Path.of("/etc"))) {
    paths = stream.toList();
}
// use paths


I suggest to add a new default method to Stream interface named `consumeAndClose`, which allows performing terminal stream operation and closing the stream at the same time. It may look like this:


    default <R> R consumeAndClose(Function<? super Stream<T>, ? extends R> function) {
        Objects.requireNonNull(function);
        try(this) {
            return function.apply(this);
        }
    }


Now, it will be possible to get the list of the files in the fluent manner:


List<Path> list = Files.list(Path.of("/etc")).consumeAndClose(Stream::toList);

-------------

Commit messages:
 - Fix tests
 - 8274412: Add a method to Stream API to consume and close the stream without using try-with-resources

Changes: https://git.openjdk.java.net/jdk/pull/5796/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5796&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274412
  Stats: 140 lines in 5 files changed: 135 ins; 0 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5796.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5796/head:pull/5796

PR: https://git.openjdk.java.net/jdk/pull/5796