syntax_data: {"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":"UNSAFE_OP_IN_UNSAFE_FN,"}]}
source_snippet:                 UNSAFE_OP_IN_UNSAFE_FN,
context_before:             MutationOfLayoutConstrainedField => tcx.emit_node_span_lint(
context_after:                 hir_id,