RFR: 8278028: [test-library] Warnings cleanup of the test library

[Roger Riggs]

Compilation warnings of the test library introduce noise in test output and should be addressed or suppressed. 
Changes include:
 - SuppressWarnings("deprecation") and SuppressWarnings("removal")
 - Adding type parameters to Raw types
 - Adding a hashCode method where equals was already present

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Commit messages:
 - 8278028: [test-library] Warnings cleanup of the test library

Changes: https://git.openjdk.java.net/jdk/pull/6638/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6638&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8278028
  Stats: 23 lines in 14 files changed: 10 ins; 1 del; 12 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6638.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6638/head:pull/6638

PR: https://git.openjdk.java.net/jdk/pull/6638