syntax_data: {"ast_node_type":"other","tokens":[{"end":32,"kind":"keyword","start":0,"text":"(\"cmpxchg16b\","}]}
source_snippet:     ("cmpxchg16b", Stable, &[]),
context_before:     ("bmi2", Stable, &[]),
context_after:     ("ermsb", Unstable(sym::ermsb_target_feature), &[]),