Remove dead default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148738 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/CommandLine.cpp

@@ -882,7 +882,6 @@ bool Option::addOccurrence(unsigned pos, StringRef ArgName,
   case OneOrMore:
   case ZeroOrMore:
   case ConsumeAfter: break;
-  default: return error("bad num occurrences flag value!");
   }
 
   return handleOccurrence(pos, ArgName, Value);