Include llvm/Support/Debug.h in AdjointValue.h (swiftlang#31711)

This is needed to reference `llvm::dbgs()`.

Co-authored-by: Arnold Schwaighofer <[email protected]>

Author: dan-zheng

include/swift/SILOptimizer/Differentiation/AdjointValue.h

@@ -21,6 +21,7 @@
 #include "swift/AST/Decl.h"
 #include "swift/SIL/SILValue.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/Debug.h"
 
 namespace swift {
 namespace autodiff {