This associates debug information with the assertion sites, allowing clearer stack-traces for assertion failures and better accounting of the performance overhead of assertions.
This change also changes the assertion functions from inline to constexpr, to allow functions using them to be called from static assertions (like optional_ref::operator* in optional_ref's constexpr test).
PiperOrigin-RevId: 903309187
Change-Id: Icbe0fd9d0fe9e212036d17468e80833b95b8a82d
ac5ea999a3