[clang] [clang-tools-extra] [libcxx] [clang] Enable sized deallocation by default in C++14 onwards (PR #83774)

[Wang Pengcheng via cfe-commits]

wangpc-pp wrote:

> The `__cpp_sized_deallocation` feature test macro should be set to 201309L

This has been done.
https://github.com/llvm/llvm-project/blob/1d900e298449d43547312364751f730b7a0d07d1/clang/lib/Frontend/InitPreprocessor.cpp#L690C1-L692C1

https://github.com/llvm/llvm-project/pull/83774