[jdk17u-dev] RFR: 8277969: HttpClient SelectorManager shuts down when custom Executor rejects a task

[Goetz Lindenmaier]

I backport this for parity with 17.0.17-oracle.
The change has several follow-ups.  All these have been backported by 
Oracle, too.  I will address them as well.

Some files needed resolving, but all edits have been trivial.
I commited the clean parts in a first commit, the resolves in a second one.

Resolves in detail:
src/java.net.http/share/classes/jdk/internal/net/http/Http1Exchange.java
Resolved one chunk because of order of "abstract static"

src/java.net.http/share/classes/jdk/internal/net/http/Http1Request.java
Copyright

src/java.net.http/share/classes/jdk/internal/net/http/Http1Response.java
Copyright and order of 'static final'

src/java.net.http/share/classes/jdk/internal/net/http/HttpClientImpl.java
Resolved imports and one chunk because of order of 'static final'.

src/java.net.http/share/classes/jdk/internal/net/http/ResponseContent.java
src/java.net.http/share/classes/jdk/internal/net/http/Stream.java
Copyright


Later test-only change JDK-8295944: "Move the Http2TestServer and
related classes into a package of its own" was already backported.
It touches two of the tests added by this change. Also,
Http2TestServer was moved by this change.

The changes for Http2TestSErver from this change could be
added to the file in the new location.  Two chunks did not
apply, Copyright and the context were in the way.
Also, I applied the patches of JDK-8295944 to the two new tests.

See third change.

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

Commit messages:
 - Parts from JDK-8295944 and edits to Http2TestServer in new location.
 - Resolves
 - Backport 5291ec8d56b0e89aa96c3d53d9dcf093480cf48f

Changes: https://git.openjdk.org/jdk17u-dev/pull/3633/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3633&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8277969
  Stats: 1991 lines in 24 files changed: 1725 ins; 139 del; 127 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3633.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3633/head:pull/3633

PR: https://git.openjdk.org/jdk17u-dev/pull/3633