[jdk17u-dev] RFR: 8283626: AArch64: Set relocInfo::offset_unit to 4

[Aleksey Shipilev]

Clean backport to improve relocation density.

Additional testing:
 - [x] Linux AArch64 server fastdebug, `tier{1,2,3,4}`

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Commit messages:
 - Backport ab17f88f6ccd793b718394987f868322a2cc0d1f

Changes: https://git.openjdk.org/jdk17u-dev/pull/2040/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2040&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8283626
  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2040.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2040/head:pull/2040

PR: https://git.openjdk.org/jdk17u-dev/pull/2040