Remove unnecessary default cases in switches that cover all enum values.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147855 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Bitcode/BitCodes.h

@@ -114,7 +114,6 @@ public:
   bool hasEncodingData() const { return hasEncodingData(getEncoding()); }
   static bool hasEncodingData(Encoding E) {
     switch (E) {
-    default: assert(0 && "Unknown encoding");
     case Fixed:
     case VBR:
       return true;