Subzero: Enable Non-SFI vector cross tests.

crosstest/insertelement.h

+//===- subzero/crosstest/insertelement.h - Helper for PNaCl workaround. ---===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Helper function to work around a potential stack overflow issue.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef INSERTELEMENT_H
+#define INSERTELEMENT_H
+
+// Helper function to perform the insertelement bitcode instruction.  The PNaCl
+// ABI simplifications transform insertelement/extractelement instructions with
+// a non-constant index into something involving alloca.  This can cause a stack
+// overflow if the alloca is inside a loop.
+template <typename VectorType, typename ElementType>
+void __attribute__((noinline))
+setElement(VectorType &Value, size_t Index, ElementType Element) {
+  Value[Index] = Element;
+}
+
+#endif // INSERTELEMENT_H