Merge pull request #68476 from etcwilde/ewilde/include-variant

Author: etcwilde

include/swift/SILOptimizer/Differentiation/AdjointValue.h

@@ -25,6 +25,8 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/Debug.h"
 
+#include <variant>
+
 namespace swift {
 namespace autodiff {