RFR: 8217408: Reduce storage of duplicate identifiers in TLS vectors in SunJSSE [v2]

[Jack Hartstein]

> 8217408: Reduce storage of duplicate identifiers in TLS vectors in SunJSSE

Jack Hartstein has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 13 additional commits since the last revision:

 - Merge
 - 8217408: Reduce storage of duplicate identifiers in TLS vectors in SunJSSE
 - Changed ClientHello compression consumer loop to index by 1 instead of 2 (bytes vs shorts), and SupportedVersionsExt consumer get length to getInt8 vs getInt16
 - removed duplicate filtering in producer side constructors for AlpnExt, CertSignAlgsExt, ServNameExt, SigAlgsExt, SupGrpsExt, SupVersExt. Removed unnecessary intermediary array in consumer methods for SigAlgsExt, SupGrpsExt, SupVersExt. Improved byte array handling for compression methods in ClientHelloMessage. Overall code cleanup
 - reverted changes to produce method in AlpnExtension, CertSignAlgsExtension, SignatureAlgorithmsExtension, SupportedGroupsExtension, and SupportedVersionsExtension
 - added duplicate filtering to CertSignAlgsExtension, added first pass attempt at filtering compression methods to ClientHello. Added tests for duplicates in compression methods, CertSignAlgs, and ServerNames to test file.
 - added stream based duplicate fixes to SignatureAlgorithmExtension, SupportedGroupsExtension, and minor changes to previous fix on SupportedVersionsExtension. Added tests for SupGrp and SigAlg extensions to test file.
 - modified test file to check ALPNs, added duplicate check to SupportedGroupsSpec
 - formatting, adding ALPN check to test file
 - implemented IntStream duplicate clearing for ClientHello ciphersuites, SupportedVersionsExtensions, Stream duplicate clearing implementation for AlpnExtension
 - ... and 3 more: https://git.openjdk.java.net/jdk/compare/0288a894...0f40ea13

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4577/files
  - new: https://git.openjdk.java.net/jdk/pull/4577/files/83a887d1..0f40ea13

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4577&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4577&range=00-01

  Stats: 48739 lines in 935 files changed: 31127 ins; 13806 del; 3806 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4577.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4577/head:pull/4577

PR: https://git.openjdk.java.net/jdk/pull/4577