Remove non-const form of lookupFieldDeclForIvar.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69563 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index e04f723..e92796b 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -2400,7 +2400,8 @@
                                        ObjCInterfaceDecl *Interface,
                                        const ObjCIvarDecl *Ivar) {
   const llvm::StructLayout *Layout = GetInterfaceDeclStructLayout(Interface);
-  FieldDecl *Field = Interface->lookupFieldDeclForIvar(CGM.getContext(), Ivar);
+  const FieldDecl *Field = 
+    Interface->lookupFieldDeclForIvar(CGM.getContext(), Ivar);
   uint64_t Offset = GetIvarBaseOffset(Layout, Field);
   return llvm::ConstantInt::get(
                             CGM.getTypes().ConvertType(CGM.getContext().LongTy),