[clang] [clang] On Windows, silence warning in `WhitespaceManager` when build… (PR #187938)

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@@ -14,6 +14,7 @@
 #include "WhitespaceManager.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/ErrorHandling.h"
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owenca wrote:

Delete.

https://github.com/llvm/llvm-project/pull/187938