[libc] [llvm] [libc] Remove obsolete LIBC_HAS_BUILTIN macro (PR #86554)

[Marc Auberer via llvm-commits]

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@@ -14,7 +14,6 @@
 #include "src/__support/CPP/limits.h"        // CHAR_BIT, numeric_limits
 #include "src/__support/CPP/type_traits.h"   // is_unsigned_v
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
-#include "src/__support/macros/config.h"     // LIBC_HAS_BUILTIN
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marcauberer wrote:

Done.

https://github.com/llvm/llvm-project/pull/86554