PNaCl: Add NoAlias attributes in ExpandByVal and ExpandVarArgs passes

lib/Transforms/NaCl/ExpandVarArgs.cpp

Index: lib/Transforms/NaCl/ExpandVarArgs.cpp
diff --git a/lib/Transforms/NaCl/ExpandVarArgs.cpp b/lib/Transforms/NaCl/ExpandVarArgs.cpp
index cbafbc275741af9a60b8fc59715cd01131412c6e..429e694c07bcd28b8bdea79e06b5bfc1df42dc23 100644
--- a/lib/Transforms/NaCl/ExpandVarArgs.cpp
+++ b/lib/Transforms/NaCl/ExpandVarArgs.cpp
@@ -203,6 +203,8 @@ static bool ExpandVarArgCall(InstType *Call, DataLayout *DL) {
     // AttributeSets use 1-based indexing.
     Attrs.push_back(Call->getAttributes().getParamAttributes(I + 1));
   }
+  Attrs.push_back(AttributeSet::get(*Context, FuncType->getNumParams() + 1,
+                                    Attribute::NoAlias));
   for (unsigned I = FuncType->getNumParams();
        I < Call->getNumArgOperands(); ++I) {
     Value *ArgVal = Call->getArgOperand(I);