Remove code path that's dead after r358835

llvm-svn: 362333
diff --git a/llvm/lib/Demangle/MicrosoftDemangle.cpp b/llvm/lib/Demangle/MicrosoftDemangle.cpp
index 425c7d3..ed9052f 100644
--- a/llvm/lib/Demangle/MicrosoftDemangle.cpp
+++ b/llvm/lib/Demangle/MicrosoftDemangle.cpp
@@ -1086,10 +1086,8 @@
 }
 
 static void outputHex(OutputStream &OS, unsigned C) {
-  if (C == 0) {
-    OS << "\\x00";
-    return;
-  }
+  assert (C != 0);
+
   // It's easier to do the math if we can work from right to left, but we need
   // to print the numbers from left to right.  So render this into a temporary
   // buffer first, then output the temporary buffer.  Each byte is of the form