[jdk17u-dev] RFR: 8358764: (sc) SocketChannel.close when thread blocked in read causes connection to be reset (win)

[Goetz Lindenmaier]

I backport this for parity with 17.0.18-oracle.

Needed resolve and adaptions:

Net.java:  resolved static initializer.
SocketChannelImpl.java: In implCloseBlockingMode(), the code guarded by the new condition is not in 17. Omitted.
Net.c: Copyright.

The test exercises platform and virtual threads.
I simplified this to what is supported in 17.
See extra commit.

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Commit messages:
 - Remove modern Thread code
 - backport 83f9c250221f707be484e0163fe9040f99474412

Changes: https://git.openjdk.org/jdk17u-dev/pull/4076/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=4076&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8358764
  Stats: 226 lines in 5 files changed: 218 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/4076.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/4076/head:pull/4076

PR: https://git.openjdk.org/jdk17u-dev/pull/4076