syntax_data: {"ast_node_type":"variable","tokens":[{"end":47,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let first = (off.bytes() / 8) as usize;
context_before:         // Fill in `cls` for scalars (Int/Sse) and vectors (Sse).
context_after:         let last = ((off.bytes() + layout.size.bytes() - 1) / 8) as usize;