syntax_data: {"ast_node_type":"other","tokens":[{"end":17,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // FEAT_JSCVT
context_before:     ("i8mm", Stable, &[]),
context_after:     // Rust ties FP and Neon: https://github.com/rust-lang/rust/pull/91608