RFR: 8301169: java/net/httpclient/ThrowingSubscribersAsInputStream.java, ThrowingSubscribersAsInputStreamAsync.java, and other httpclient tests failing on windows: Unable to establish loopback connection [v2]

[Daniel Fuchs]

> The HttpClient Throwing* tests are creating a lot of HttpClient instances and have been observed failing on Windows from time to time with the error:  Unable to establish loopback connection.
> 
> To try and mitigate the issue here is a change that will wait for the previous client to be GC'ed before creating the new one. Hopefully that should reduce the cases where these tests fail due to resource exhaustion.

Daniel Fuchs has updated the pull request incrementally with one additional commit since the last revision:

  Added comments

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13644/files
  - new: https://git.openjdk.org/jdk/pull/13644/files/62792d05..f84b93bb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13644&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13644&range=00-01

  Stats: 42 lines in 3 files changed: 42 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13644.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13644/head:pull/13644

PR: https://git.openjdk.org/jdk/pull/13644