syntax_data: {"ast_node_type":"other","tokens":[{"end":66,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // FIXME(#28160) there is an interesting semantics
context_before:             ExprKind::AssignOp { op, lhs, rhs } => {
context_after:                 // question raised here -- should we "freeze" the