Also standardize the license comment in several files where it was different from what we normally do.
This was actually already implemented in the initial version of std::expected, but this patch adds test coverage and makes it more explicit that we intend to make these functions noexcept.
std::expected
Implement `std::expected` https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0323r12.html Added tests Differential Revision: https://reviews.llvm.org/D124516 address comment