Fix a crash. Make sure TLI is not null.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43384 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index d81ea2b..c5fdc09 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -972,7 +972,7 @@
     AM.Scale = Scale;
 
     // If load[imm+r*scale] is illegal, bail out.
-    if (!TLI->isLegalAddressingMode(AM, AccessTy))
+    if (TLI && !TLI->isLegalAddressingMode(AM, AccessTy))
       return false;
   }
   return true;