[libcxx] [llvm] [libc++] Refactor the configuration macros to being always defined (PR #112094)

[Louis Dionne via llvm-commits]

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@@ -741,24 +741,24 @@ config_define(${LIBCXX_ABI_VERSION} _LIBCPP_ABI_VERSION)
 config_define(${LIBCXX_ABI_NAMESPACE} _LIBCPP_ABI_NAMESPACE)
 config_define_if(LIBCXX_ABI_FORCE_ITANIUM _LIBCPP_ABI_FORCE_ITANIUM)
 config_define_if(LIBCXX_ABI_FORCE_MICROSOFT _LIBCPP_ABI_FORCE_MICROSOFT)
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ldionne wrote:

I would like us to make these 0-1 macros (and the threading macros below) as well just to make everything consistent. Otherwise this is very confusing.

https://github.com/llvm/llvm-project/pull/112094