[clang] [clang][CIR] Lower SVE svpfalse_b and add tests (PR #228789)

[Vicky Nguyen via cfe-commits]

iamvickynguyen wrote:

It's strange that I can't merge this PR :( Would you mind helping me with this please @banach-space ?

<img width="1370" height="741" alt="image" src="https://github.com/user-attachments/assets/7664a7d8-3847-483c-8fe0-2a7743e0d91c" />


https://github.com/llvm/llvm-project/pull/228789