syntax_data: {"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"DeclareLetBindings::LetNotPermitted"}]}
source_snippet:             DeclareLetBindings::LetNotPermitted => {
context_before:             DeclareLetBindings::No => {} // Caller is responsible for bindings.
context_after:                 self.tcx.dcx().span_bug(expr_span, "let expression not expected in this context")