Function w8a16_gemm_pipelined_m64 

pub fn w8a16_gemm_pipelined_m64(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    input: DevicePtr,
    weight: DevicePtr,
    block_scale: DevicePtr,
    output: DevicePtr,
    m: u32,
    n: u32,
    k: u32,
    stream: u64,
) -> Result<()>

2026-09-26: Contiguous launch of w8a16_gemm_pipelined_m64 (pitches k and n). Same signature as super::w8a16_gemm_pipelined.