RFR: CODETOOLS-7902920: jcstress: Rework binary link client/server for lower latency [v2]

[Aleksey Shipilev]

> Profiling of current "-m sanity" runs shows that we are spending 10..100ms per JVM in dealing with Java serialization and network transfers. Since the binary link is rather simple, we can hand-craft a binary protocol that would alleviate these costs.

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Revert unnecessary changes

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Changes:
  - all: https://git.openjdk.java.net/jcstress/pull/48/files
  - new: https://git.openjdk.java.net/jcstress/pull/48/files/f9f9bd3b..7acdd913

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jcstress&pr=48&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jcstress&pr=48&range=00-01

  Stats: 5 lines in 2 files changed: 4 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jcstress/pull/48.diff
  Fetch: git fetch https://git.openjdk.java.net/jcstress pull/48/head:pull/48

PR: https://git.openjdk.java.net/jcstress/pull/48