RFR: 8288473: Remove unused frame::set_pc_preserve_deopt methods

[Coleen Phillimore]

Please review this trivial change to remove unused functions.

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Commit messages:
 - 8288473: Remove unused frame::set_pc_preserve_deopt methods

Changes: https://git.openjdk.org/jdk/pull/10233/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10233&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8288473
  Stats: 18 lines in 2 files changed: 0 ins; 17 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10233.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10233/head:pull/10233

PR: https://git.openjdk.org/jdk/pull/10233