syntax_data: {"ast_node_type":"variable","tokens":[{"end":75,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let field_layout = variant_layout.field(cx, field_idx);
context_before:                     let field_name = coroutine.field_names[*local];
context_after:                     let offset = variant_layout.fields.offset(field_idx);