RFR: 8293961: Unused ClassPathZipEntry::contents_do

[Matias Saavedra Silva]

Removed unused function and ran tier1 to verify. Please review.

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Commit messages:
 - 8293961: Unused ClassPathZipEntry::contents_do

Changes: https://git.openjdk.org/jdk/pull/10413/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10413&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293961
  Stats: 13 lines in 2 files changed: 0 ins; 13 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/10413.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10413/head:pull/10413

PR: https://git.openjdk.org/jdk/pull/10413