PNaCl translator: combine insertelement / extractelement patterns generated by the toolchain into s…

tools/pnacl-llc/pnacl-llc.cpp

Index: tools/pnacl-llc/pnacl-llc.cpp
diff --git a/tools/pnacl-llc/pnacl-llc.cpp b/tools/pnacl-llc/pnacl-llc.cpp
index 35cddefa3f7e51651813c3062a5c3ad022bbf919..82ecdb45234c0f029074f3c86953abb051b37f8b 100644
--- a/tools/pnacl-llc/pnacl-llc.cpp
+++ b/tools/pnacl-llc/pnacl-llc.cpp
@@ -420,6 +420,10 @@ static int runCompilePasses(Module *mod,
     TLI->disableAllFunctions();
   PM->add(TLI);
 
+  // Allow subsequent passes to better optimize vector instructions.
+  // This pass uses the TargetLibraryInfo above.
+  PM->add(createCombineVectorInstructionsPass());
+
   // Add intenal analysis passes from the target machine.
   Target.addAnalysisPasses(*PM.get());