[jdk17u-dev] RFR: 8320276: Improve class initialization barrier in TemplateTable::_new

[Matt]

This PR backports 8320276 to support backporting 8338379, see the comment thread linked below. This was a clean backport, though reviewers may want to confirm that the decision to include [this function](https://github.com/openjdk/jdk17u-dev/blob/f19121cc65199f2052c69747dfa7ae8d209596f4/src/hotspot/cpu/ppc/vm_version_ppc.hpp#L135) was correct. 

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### Progress
- [ ] Change must be properly reviewed (1 review required, with at least 1 [Reviewer](https://openjdk.org/bylaws#reviewer))
- [x] Change must not contain extraneous whitespace
- [x] Commit message must refer to an issue
- [ ] [JDK-8320276](https://bugs.openjdk.org/browse/JDK-8320276) needs maintainer approval



### Reviewing
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Commit messages:
 - Backport 409a39ec8da83d6a0895e7e213604455ebf50485

Changes: https://git.openjdk.org/jdk17u-dev/pull/3508/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3508&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8320276
  Stats: 17 lines in 6 files changed: 8 ins; 2 del; 7 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3508.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3508/head:pull/3508

PR: https://git.openjdk.org/jdk17u-dev/pull/3508