{"ast_node_type":"other","tokens":[{"end":77,"kind":"keyword","start":0,"text":"PrimTy::Float(FloatTy::F16)"}]}
                    PrimTy::Float(FloatTy::F16) if !tcx.features().f16() => {
                let gate_err_sym_msg = match prim {
                        Some((sym::f16, "the type `f16` is unstable"))