[lld] [LLD][COFF] Detect weak reference cycles. (PR #104463)

[Martin Storsjö via llvm-commits]

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@@ -13,6 +13,7 @@
 #include "lld/Common/Memory.h"
 #include "lld/Common/Strings.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallSet.h"
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mstorsjo wrote:

The include of `SmallSet.h` is leftover when using `DenseMap`. (And if we don't already do it, we probably should include `DenseMap.h` explicitly somewhere?)

https://github.com/llvm/llvm-project/pull/104463