syntax_data: {"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // A constant that came from a const generic but was then used as an argument to
context_before:             mir::Const::Ty(_, c) => match c.kind() {
context_after:                 // old-style simd_shuffle (passing as argument instead of as a generic param).