{"ast_node_type":"variable","tokens":[{"end":63,"kind":"keyword","start":0,"text":"let"}]}
        let zero_byte = bx.context.new_rvalue_zero(bx.u8_type);
        // Step 1: Generate pre-reversed low and high nibbles as a vector.
        let hi_nibble_elements: Vec<_> = (0u8..16)