RFR: 8293064: Remove unused NET_xxx functions [v2]

[Darragh Clarke]

> No tests were affected so this is purely a removal PR apart from updating copyright headers.
> I ran tests for Tier 1,2&3 and everything seems to be passing

Darragh Clarke has updated the pull request incrementally with one additional commit since the last revision:

  removed more functions

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/10343/files
  - new: https://git.openjdk.org/jdk/pull/10343/files/caa215ff..2fe5aedb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10343&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10343&range=00-01

  Stats: 291 lines in 4 files changed: 0 ins; 291 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/10343.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10343/head:pull/10343

PR: https://git.openjdk.org/jdk/pull/10343