syntax_data: {"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"fixed_x18:"}]}
source_snippet:     fixed_x18: bool = (false, parse_bool, [TRACKED TARGET_MODIFIER],
context_before:         (default: no)"),
context_after:         "make the x18 register reserved on AArch64 (default: no)"),