[clang] Update stdckdint.h and make it available in pre-C23 modes. (PR #69649)

[Jessica Clarke via cfe-commits]

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@@ -21,9 +21,6 @@
 
 /* C23 7.20.1 Defines several macros for performing checked integer arithmetic*/
 
-#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L
-#define __STDC_VERSION_STDCKDINT_H__ 202311L
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jrtc27 wrote:

This needs to stay, `__STDC_VERSION_STDCKDINT_H__` is defined by C23, not just something Clang invented

https://github.com/llvm/llvm-project/pull/69649