back out r98957, it broke http://smooshlab.apple.com:8010/builders/clang-x86_64-darwin10-fnt/builds/703 in the nightly test suite

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98958 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/PruneEH.cpp b/lib/Transforms/IPO/PruneEH.cpp
index 161246b..3ae771c 100644
--- a/lib/Transforms/IPO/PruneEH.cpp
+++ b/lib/Transforms/IPO/PruneEH.cpp
@@ -168,7 +168,7 @@
   for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
     if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator()))
       if (II->doesNotThrow()) {
-        SmallVector<Value*, 8> Args(II->op_begin(), II->op_end() - 3);
+        SmallVector<Value*, 8> Args(II->op_begin()+3, II->op_end());
         // Insert a call instruction before the invoke.
         CallInst *Call = CallInst::Create(II->getCalledValue(),
                                           Args.begin(), Args.end(), "", II);