syntax_data: {"ast_node_type":"other","tokens":[{"end":59,"kind":"keyword","start":0,"text":"(\"thumb-mode\","}]}
source_snippet:     ("thumb-mode", Unstable(sym::arm_target_feature), &[]),
context_before:     // #[target_feature].
context_after:     ("thumb2", Unstable(sym::arm_target_feature), &[]),