[llvm] [RISCV] Implement RISCVTTIImpl::getPreferredAddressingMode for HasVendorXCVmem (PR #120533)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-aarch64-sve-vls-2stage` running on `linaro-g3-01` while building `llvm` at step 11 "build stage 2".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/4/builds/4442

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 11 (build stage 2) failure: 'ninja' (failure)

```

</details>

https://github.com/llvm/llvm-project/pull/120533