RFR (S): 8230854: Cleanup SuppressWarnings in test lib and remove noisy traces in StreamPumper

[Langer, Christoph]

Hi,

please review this cleanup in test.lib.

One part is the removal/cleanup of @SuppressWarnings annotations. Some are unnecessary and in Utils.java an unchecked warning can be quiesced.

Furthermore, when analyzing some test outputs lately, I got annoyed by stack traces like the following when using jdk.test.lib.process.StreamPumper. I think they are of no particular value and could be suppressed.

java.io.IOException: Stream closed
at java.base/java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:169)
at java.base/java.io.BufferedInputStream.read(BufferedInputStream.java:335)
at java.base/java.io.BufferedInputStream.fill(BufferedInputStream.java:245)
at java.base/java.io.BufferedInputStream.read1(BufferedInputStream.java:285)
at java.base/java.io.BufferedInputStream.read(BufferedInputStream.java:344)
at java.base/java.io.FilterInputStream.read(FilterInputStream.java:107)
at jdk.test.lib.process.StreamPumper.run(StreamPumper.java:109)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.lang.Thread.run(Thread.java:830)

Bug: https://bugs.openjdk.java.net/browse/JDK-8230854
Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8230854.0/

Thanks
Christoph