RFR: 8368724: RISC-V: Remove AvoidUnalignedAccesses Flag [v6]

[Anjian Wen]

> According to the discuss in https://github.com/openjdk/jdk/pull/27445#, we can use UseUnalignedAccesses and !UseUnalignedAccesses to cover the AvoidUnalignedAccesses Flag, so I Remove the AvoidUnalignedAccesses Flag in this patch

Anjian Wen has updated the pull request incrementally with one additional commit since the last revision:

  modify the global flag change

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Changes:
  - all: https://git.openjdk.org/jdk/pull/27510/files
  - new: https://git.openjdk.org/jdk/pull/27510/files/be963cdc..6eb1dd95

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27510&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27510&range=04-05

  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27510.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27510/head:pull/27510

PR: https://git.openjdk.org/jdk/pull/27510