RFR: JDK-8155039 Simplify code to setup SSLContextImpl and TrustManagerFactoryImpl

[Mark Powers]

https://bugs.openjdk.org/browse/JDK-8155039

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Commit messages:
 - fourth iteration
 - third iteration
 - second iteration
 - first iteration

Changes: https://git.openjdk.org/jdk/pull/9542/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9542&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8155039
  Stats: 85 lines in 4 files changed: 48 ins; 29 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/9542.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9542/head:pull/9542

PR: https://git.openjdk.org/jdk/pull/9542