syntax_data: {"ast_node_type":"other","tokens":[{"end":71,"kind":"keyword","start":0,"text":"(\"sme\","}]}
source_snippet:     ("sme", Unstable(sym::aarch64_unstable_target_feature), &["bf16"]),
context_before:     // FEAT_SME
context_after:     // FEAT_SME_B16B16