Integrated: clean up to warnings related code

[Vicente Romero]

clean up to warnings for universal tvars

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Commit messages:
 - cleaning up warnings related code

Changes: https://git.openjdk.java.net/valhalla/pull/655/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=655&range=00
  Stats: 71 lines in 5 files changed: 63 ins; 5 del; 3 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/655.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/655/head:pull/655

PR: https://git.openjdk.java.net/valhalla/pull/655