Replace some assert(0)'s with llvm_unreachable.

llvm-svn: 211141
diff --git a/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h b/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
index d7ec6eb..7934761 100644
--- a/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
+++ b/llvm/lib/Target/ARM/ARMMachineFunctionInfo.h
@@ -220,7 +220,7 @@
 
   void recordCPEClone(unsigned CPIdx, unsigned CPCloneIdx) {
     if (!CPEClones.insert(std::make_pair(CPCloneIdx, CPIdx)).second)
-      assert(0 && "Duplicate entries!");
+      llvm_unreachable("Duplicate entries!");
   }
 
   unsigned getOriginalCPIdx(unsigned CloneIdx) const {