[llvm] [AMDGPU] Select v_lshl_add_u32 instead of v_mul_lo_u32 by constant (PR #71035)

[Nikita Popov via llvm-commits]

nikic wrote:

FYI I landed https://github.com/llvm/llvm-project/commit/f9404a1b57a5e6050138ceeea327cfd2a4c84f06 to fix the build.

https://github.com/llvm/llvm-project/pull/71035