syntax_data: {"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"ExpnKind::Macro(MacroKind::Bang,"}]}
source_snippet:             ExpnKind::Macro(MacroKind::Bang, _) => {
context_before:             ExpnKind::AstPass(_) | ExpnKind::Desugaring(_) => true, // well, it's "external"
context_after:                 // Dummy span for the `def_site` means it's an external macro.