RFR: 8339168: Optimize ClassFile Util slotSize [v7]

[Shaojin Wen]

> A small optimization to improve the performance of jdk.internal.classfile.impl.Util#slotSize/isDoubleSlot

Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:

  optimize parameterSlots

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20747/files
  - new: https://git.openjdk.org/jdk/pull/20747/files/550216ab..661639ab

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20747&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20747&range=05-06

  Stats: 13 lines in 2 files changed: 5 ins; 4 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/20747.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20747/head:pull/20747

PR: https://git.openjdk.org/jdk/pull/20747