RFR: 8306455: Wrong majorVersion for multiple attributes in Classfile API

[Chen Liang]

Spotted the typo for BootstrapMethods, and another review over the API exposed the typo on PermittedSubclasses.

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Commit messages:
 - 8306455: Wrong majorVersion for multiple attributes in Classfile API

Changes: https://git.openjdk.org/jdk/pull/13536/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13536&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8306455
  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/13536.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13536/head:pull/13536

PR: https://git.openjdk.org/jdk/pull/13536