Fix warning building in optimized mode

llvm-svn: 13190
diff --git a/llvm/lib/Bytecode/Reader/InstructionReader.cpp b/llvm/lib/Bytecode/Reader/InstructionReader.cpp
index d66b12c..5033a32 100644
--- a/llvm/lib/Bytecode/Reader/InstructionReader.cpp
+++ b/llvm/lib/Bytecode/Reader/InstructionReader.cpp
@@ -319,6 +319,7 @@
           IdxTy = Type::UIntTyID;
         else {
           switch (ValIdx & 3) {
+          default:
           case 0: IdxTy = Type::UIntTyID; break;
           case 1: IdxTy = Type::IntTyID; break;
           case 2: IdxTy = Type::ULongTyID; break;