syntax_data: {"ast_node_type":"variable","tokens":[{"end":69,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let rest_size = size - Size::from_bytes(8) * prefix_index as u64;
context_before:     // Extract first 8 chunks as the prefix
context_after:     arg.cast_to(CastTarget::prefixed(prefix, Uniform::new(Reg::i64(), rest_size)));