syntax_data: {"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"no_trait_vptr:"}]}
source_snippet:     no_trait_vptr: bool = (false, parse_no_value, [TRACKED],
context_before:         "don't steal the THIR when we're done with it; useful for rustc drivers (default: no)"),
context_after:         "disable generation of trait vptr in vtable for upcasting"),