Add missing #include's to cctype when using isdigit/alpha/etc.

llvm-svn: 192519
diff --git a/llvm/lib/Object/COFFObjectFile.cpp b/llvm/lib/Object/COFFObjectFile.cpp
index 67b8e6b..3d1e62e 100644
--- a/llvm/lib/Object/COFFObjectFile.cpp
+++ b/llvm/lib/Object/COFFObjectFile.cpp
@@ -18,6 +18,7 @@
 #include "llvm/ADT/Triple.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include <cctype>
 
 using namespace llvm;
 using namespace object;