Re-enable extension optimization pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93313 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 4ab6a94..733995f 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -325,6 +325,7 @@
                  /* allowDoubleDefs= */ true);
 
   if (OptLevel != CodeGenOpt::None) {
+    PM.add(createOptimizeExtsPass());
     if (!DisableMachineLICM)
       PM.add(createMachineLICMPass());
     if (!DisableMachineSink)