Function recognize_lut_attention 

pub fn recognize_lut_attention(
    stmts: &[Stmt<'_>],
    interner: &Interner,
) -> Option<LutAttentionSpec>

Recognize the lut attention block: a Splice holding the LUT weight read and a floor-division write, its head loop and cache bound the single-query attention’s (attention_heads, masked_length). Its operands, the tensors it reads by index and does not bind, are Q, K, E, V in program order; the table is the one the LUT read names.