This cast is not necessary any more (llvm api change).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210206 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CodeGenModule.cpp

@@ -231,7 +231,7 @@ static const llvm::GlobalObject *getAliasedGlobal(const llvm::GlobalAlias &GA) {
   llvm::SmallPtrSet<const llvm::GlobalAlias*, 4> Visited;
   const llvm::Constant *C = &GA;
   for (;;) {
-    C = cast<llvm::Constant>(C->stripPointerCasts());
+    C = C->stripPointerCasts();
     if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
       return GO;
     // stripPointerCasts will not walk over weak aliases.