[jdk17u] RFR: 8277981: String Deduplication table is never cleaned up due to bad dead_factor_for_cleanup

[Aleksey Shipilev]

Clean backport to fix a math problem in strdedup heuristics that leads to observable memory leaks.

Additional testing:
 - [x] Linux x86_64 fastdebug `tier1` with `-XX:+UseStringDeduplication`
 - [x] Linux x86_64 fastdebug `tier2` with `-XX:+UseStringDeduplication`
 - [x] Linux x86_64 fastdebug `tier3` with `-XX:+UseStringDeduplication`

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Commit messages:
 - Backport 8d7958e46969fd59df7bc6dd1cbe31ae63686b05

Changes: https://git.openjdk.java.net/jdk17u/pull/316/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=316&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277981
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/316.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/316/head:pull/316

PR: https://git.openjdk.java.net/jdk17u/pull/316