[libc-commits] [libc] [libc][NFC] rename LONG_DOUBLE_IS_DOUBLE into LIBC_LONG_DOUBLE_IS_DOUBLE (PR #73948)

[Guillaume Chatelet via libc-commits]

gchatelet wrote:

Not a super interesting PR but I intend to make sure libc properties are formatted consistently. Let me know if you have a better name to suggest.

https://github.com/llvm/llvm-project/pull/73948