https://issues.dlang.org/show_bug.cgi?id=24414

          Issue ID: 24414
           Summary: ImportC: undefined identifier `__builtin_clz`
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: alphaglosined@gmail.com

Another ImportC intrinsic that is missing ``__builtin_clz``.

>From the NewsGroup comment:
https://forum.dlang.org/post/sotawneftuxhgxmmeuoo@forum.dlang.org

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