Don't delete one more instruction than we're allowed to. This should …

…fix the

Darwin bootstrap. Testcase exists but isn't fully reduced, I expect to commit
the testcase this evening.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160693 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/IPO/GlobalOpt.cpp

@@ -442,12 +442,14 @@ static bool CleanupPointerRootUsers(GlobalVariable *GV) {
       Dead[i].second->eraseFromParent();
       Instruction *I = Dead[i].first;
       do {
+	if (isAllocationFn(I))
+	  break;
         Instruction *J = dyn_cast<Instruction>(I->getOperand(0));
         if (!J)
           break;
         I->eraseFromParent();
         I = J;
-      } while (!isAllocationFn(I));
+      } while (1);
       I->eraseFromParent();
     }
   }