Fixed few warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160419 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/MachOObject.cpp b/lib/Object/MachOObject.cpp
index 00dea3f..90faa3b 100644
--- a/lib/Object/MachOObject.cpp
+++ b/lib/Object/MachOObject.cpp
@@ -44,7 +44,8 @@
   }
 
   // Check whether we can return a direct pointer.
-  struct_type *Ptr = (struct_type *) (Buffer.data() + Base);
+  struct_type *Ptr =
+    const_cast<struct_type *>((const struct_type *)(Buffer.data() + Base));
   if (!MOO.isSwappedEndian()) {
     Res = Ptr;
     return;