RFR: 8336267: Method and Constructor signature parsing can be shared on the root object [v2]

[Chen Liang]

> A straightforward optimization, to share the signature parsing of method, constructor, and field between the root and the copied objects, like how method handle accessors are shared.

Chen Liang has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:

 - Merge branch 'master' of https://github.com/openjdk/jdk into feature/member-sig-share
 - 8336267: Method and Constructor signature parsing can be shared on the root object

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Changes: https://git.openjdk.org/jdk/pull/20179/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20179&range=01
  Stats: 30 lines in 3 files changed: 19 ins; 0 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/20179.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20179/head:pull/20179

PR: https://git.openjdk.org/jdk/pull/20179