syntax_data: {"ast_node_type":"variable","tokens":[{"end":57,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let offset = layout.fields.offset(field_idx);
context_before:             let field_layout = layout.field(cx, field_idx);
context_after:             upvars_size = upvars_size.max(offset + field_layout.size);