Move getOpcodeName from the various target InstPrinters into the superclass MCInstPrinter.

All implementations used the same code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153866 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCInstPrinter.cpp b/lib/MC/MCInstPrinter.cpp
index 3060ad6..847bcc0 100644
--- a/lib/MC/MCInstPrinter.cpp
+++ b/lib/MC/MCInstPrinter.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/MC/MCInstPrinter.h"
+#include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -20,7 +21,7 @@
 /// getOpcodeName - Return the name of the specified opcode enum (e.g.
 /// "MOV32ri") or empty if we can't resolve it.
 StringRef MCInstPrinter::getOpcodeName(unsigned Opcode) const {
-  return "";
+  return MII.getName(Opcode);
 }
 
 void MCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {