syntax_data: {"ast_node_type":"variable","tokens":[{"end":100,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                 let args = InlineConstArgs::new(tcx, InlineConstArgsParts { parent_args, ty }).args;
context_before:                     tcx.erase_regions(GenericArgs::identity_for_item(tcx, typeck_root_def_id));