syntax_data: {"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":"FieldsShape::Primitive"}]}
source_snippet:             FieldsShape::Primitive => {
context_before:         BackendRepr::ScalarPair(..) | BackendRepr::Memory { .. } => match arg_layout.fields {
context_after:                 unreachable!("aggregates can't have `FieldsShape::Primitive`")