RFR: 8270317: Large Allocation in CipherSuite

[Clive Verghese]

### Benchmark results 

I have benchmarked 3 cases.

1. The current situation. 

Benchmark                                                        (cipherSuite)  Mode  Cnt    Score   Error  Units
CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  avgt   25  124.783 ? 2.050  ns/op
CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  avgt   25  125.403 ? 0.554  ns/op
CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  avgt   25  127.117 ? 0.789  ns/op
CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  avgt   25  127.869 ? 1.112  ns/op


2. Use `static final array` instead of calling `CipherSuite.values` each time. 

Benchmark                                                        (cipherSuite)  Mode  Cnt   Score   Error  Units
CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  avgt   25  10.146 ? 0.252  ns/op
CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  avgt   25  30.501 ? 0.207  ns/op
CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  avgt   25  47.375 ? 0.150  ns/op
CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  avgt   25  55.887 ? 3.786  ns/op


3. Using Hashmap for lookup instead of iterating through the array each time. (Method in this PR)

Benchmark                                                        (cipherSuite)  Mode  Cnt   Score   Error  Units
CipherSuiteBench.benchmarkCipherSuite                   TLS_AES_256_GCM_SHA384  avgt   25  13.533 ? 0.148  ns/op
CipherSuiteBench.benchmarkCipherSuite  TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384  avgt   25  11.269 ? 0.147  ns/op
CipherSuiteBench.benchmarkCipherSuite      TLS_DHE_DSS_WITH_AES_128_CBC_SHA256  avgt   25  11.507 ? 0.107  ns/op
CipherSuiteBench.benchmarkCipherSuite         TLS_DHE_RSA_WITH_AES_256_CBC_SHA  avgt   25  10.932 ? 0.146  ns/op


I have picked 4 cipher suite from the start of the list and are roughly 10 positions apart. I have opted to go with HashMap for name and id lookup as they provide a more consistent times and benchmarks are similar for the first few cipher suits in the enum as well.

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Commit messages:
 - 8270317: Large Allocation in CipherSuite

Changes: https://git.openjdk.java.net/jdk/pull/4783/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4783&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8270317
  Stats: 100 lines in 2 files changed: 72 ins; 19 del; 9 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4783.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4783/head:pull/4783

PR: https://git.openjdk.java.net/jdk/pull/4783