bf9e73d56e
- Lexer tokenizes 'a as tkLifetime - Parser accepts lifetimes in type params <'a> and reference types &'a T / &'a mut T - AST TypeExpr has refLifetime field for tekRef/tekMutRef - TypeParam gains isLifetime flag for generic monomorphization - Sema infers lifetime params as no-op dummy values; unwraps pointee types for params inside refs - HIR lower skips lifetime params when generating mangled names and substitution tables - &mut expr syntax supported in parser (consumed as part of unary &)