Convert assert(0) to llvm_unreachable

llvm-svn: 149967
diff --git a/llvm/lib/MC/MCInstPrinter.cpp b/llvm/lib/MC/MCInstPrinter.cpp
index 2317a28..3060ad6 100644
--- a/llvm/lib/MC/MCInstPrinter.cpp
+++ b/llvm/lib/MC/MCInstPrinter.cpp
@@ -10,6 +10,7 @@
 #include "llvm/MC/MCInstPrinter.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
@@ -23,7 +24,7 @@
 }
 
 void MCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
-  assert(0 && "Target should implement this");
+  llvm_unreachable("Target should implement this");
 }
 
 void MCInstPrinter::printAnnotation(raw_ostream &OS, StringRef Annot) {