syntax_data: {"ast_node_type":"other","tokens":[{"end":36,"kind":"keyword","start":0,"text":"(\"sse4.2\","}]}
source_snippet:     ("sse4.2", Stable, &["sse4.1"]),
context_before:     ("sse4.1", Stable, &["ssse3"]),
context_after:     ("sse4a", Unstable(sym::sse4a_target_feature), &["sse3"]),