[libcxx-commits] [libcxx] Reapply "[libc++] Avoid constructing additional objects when using map::at" (#160738) (PR #161485)

[Nico Weber via libcxx-commits]

nico wrote:

(Do you happen to have a link to the LLVM fix? This breaks some of our code – likely our fault, but it'd be convenient to see what other fixes that this required looked like :))

https://github.com/llvm/llvm-project/pull/161485