Fix linker error by resolving regions for main return type obligations This PR fix linker error by resolving regions for main return type obligations as discussed in https://github.com/rust-lang/rust/issues/148421 Added a final check . Now the compiler double-checks the lifetimes for main right away. If they don't work it stops and gives the user a clean compiler error instead of a linker crash. Fixes https://github.com/rust-lang/rust/issues/148421.