syntax_data: {"ast_node_type":"variable","tokens":[{"end":77,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let allocation = tcx.allocate_bytes_dedup(data, CTFE_ALLOC_SALT);
context_before:             let len = data.len();
context_after:             ConstValue::Slice { alloc_id: allocation, meta: len.try_into().unwrap() }