syntax_data: {"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // value, so it's implicitly immutable.)
context_before:             // argument was passed indirectly. (If the argument is passed directly, it's an SSA
context_after:             if let &mut PassMode::Indirect { ref mut attrs, .. } = &mut arg.mode {