RFR: 8367137: RISC-V: Detect Zicboz block size via hwprobe [v6]

[Dingli Zhang]

> Hi,
> Can you help to review this patch? Thanks!
> 
> We can extends RISC-V hwprobe support to include `RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`.
> The probed value is recorded in VM_Version::zicboz_block_size and then used to set the zicboz_block_size.
> This ensures correct usage of the Zicboz extension, as block zeroing instructions operate on cache-line granularity.
> 
> FYI: https://docs.kernel.org/arch/riscv/hwprobe.html

Dingli Zhang has updated the pull request incrementally with one additional commit since the last revision:

  Add some extra change at the use of zero_dcache_blocks

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/27155/files
  - new: https://git.openjdk.org/jdk/pull/27155/files/5a167d6b..e8694344

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27155&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27155&range=04-05

  Stats: 5 lines in 2 files changed: 1 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/27155.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27155/head:pull/27155

PR: https://git.openjdk.org/jdk/pull/27155