syntax_data: {"ast_node_type":"other","tokens":[{"end":45,"kind":"keyword","start":0,"text":"Self::kreg"}]}
source_snippet:             Self::kreg | Self::kreg0 => None,
context_before:             Self::zmm_reg => Some(('z', "zmm0", 512).into()),
context_after:             Self::mmx_reg | Self::x87_reg => None,