Convert assert(0) to llvm_unreachable

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149961 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 222cb30..6c837bc 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -533,7 +533,7 @@
   else if (SymbolicOp.VariantKind == LLVMDisassembler_VariantKind_None)
     MI.addOperand(MCOperand::CreateExpr(Expr));
   else
-    assert(0 && "bad SymbolicOp.VariantKind");
+    llvm_unreachable("bad SymbolicOp.VariantKind");
 
   return true;
 }