MathExtras isn't in the llvm/ADT directory but in the llvm/Support directory.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31219 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/FoldingSet.cpp b/lib/Support/FoldingSet.cpp
index d8eff37..14b524b 100644
--- a/lib/Support/FoldingSet.cpp
+++ b/lib/Support/FoldingSet.cpp
@@ -15,7 +15,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/ADT/FoldingSet.h"
-#include "llvm/ADT/MathExtras.h"
+#include "llvm/Support/MathExtras.h"
using namespace llvm;
//===----------------------------------------------------------------------===//