syntax_data: {"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // before typecheck has completed and uses `try_normalize_erasing_regions`.
context_before:     // `normalize_erasing_regions` here and another one that can be called
context_after:     let ty = match tcx.try_normalize_erasing_regions(typing_env, ty) {