[jdk17u-dev] RFR: 8270794: Avoid loading Klass* twice in TypeArrayKlass::oop_size()

[Aleksey Shipilev]

Clean backport to micro-optimize the affected path and make it easier for downstreams like Lilliput JDK 17.

Additional testing:
 - [ ] Linux AArch64 fastdebug `tier1`
 - [ ] Linux AArch64 fastdebug `tier2`

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Commit messages:
 - Backport ea49691f1dbb4f57ed0c5982f004e7aabcd15d13

Changes: https://git.openjdk.org/jdk17u-dev/pull/1527/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1527&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8270794
  Stats: 5 lines in 4 files changed: 0 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1527.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1527/head:pull/1527

PR: https://git.openjdk.org/jdk17u-dev/pull/1527