syntax_data: {"ast_node_type":"other","tokens":[{"end":29,"kind":"keyword","start":0,"text":"dcx.emit_err("}]}
source_snippet:                 dcx.emit_err(
context_before:             BorrowOfLayoutConstrainedField if unsafe_op_in_unsafe_fn_allowed => {
context_after:                     BorrowOfLayoutConstrainedFieldRequiresUnsafeUnsafeOpInUnsafeFnAllowed {