[libc-commits] [libc] [libc] Replace -nostdlib++ flag when building with gcc and add placement new operator to HermeticTestUtils.cpp. (PR #78906)

[Nick Desaulniers via libc-commits]

nickdesaulniers wrote:

gcc-13 added support for `-nostdlib++`. Perhaps it's worth using `check_cxx_compiler_flag` to check for `-nostdlib++` support, then fall back to `-nostdlib` if not?

https://github.com/llvm/llvm-project/pull/78906