{"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"(unstable,"}]}
    (unstable, powerpc_target_feature, "1.27.0", Some(44839)),
    (unstable, nvptx_target_feature, "CURRENT_RUSTC_VERSION", Some(44839)),
    (unstable, prfchw_target_feature, "1.78.0", Some(44839)),