syntax_data: {"ast_node_type":"variable","tokens":[{"end":73,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let offset = variant_layout.fields.offset(field_idx);
context_before:                     let field_layout = variant_layout.field(cx, field_idx);
context_after:                     // The struct is as large as the last field's end