CodeGenPrepare: Don't crash when TLI is not available.

This happens when codegenprepare is invoked via opt.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159457 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp
index c95d36a..cbc089a 100644
--- a/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -1133,7 +1133,8 @@
 bool CodeGenPrepare::OptimizeSelectInst(SelectInst *SI) {
   // If we have a SelectInst that will likely profit from branch prediction,
   // turn it into a branch.
-  if (DisableSelectToBranch || OptSize || !TLI->isPredictableSelectExpensive())
+  if (DisableSelectToBranch || OptSize || !TLI ||
+      !TLI->isPredictableSelectExpensive())
     return false;
 
   if (!SI->getCondition()->getType()->isIntegerTy(1) ||