syntax_data: {"ast_node_type":"other","tokens":[{"end":34,"kind":"keyword","start":0,"text":"x15:"}]}
source_snippet:         x15: reg = ["x15", "w15"],
context_before:         x14: reg = ["x14", "w14"] % restricted_for_arm64ec,
context_after:         x16: reg = ["x16", "w16"],