Change all self assignments X=X to (void)X, so that we can turn on a

new gcc warning that complains on self-assignments and
self-initializations.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122458 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/CodeEmitterGen.cpp

@@ -264,7 +264,7 @@ void CodeEmitterGen::run(raw_ostream &o) {
   o << "  const unsigned opcode = MI.getOpcode();\n"
     << "  unsigned Value = InstBits[opcode];\n"
     << "  unsigned op = 0;\n"
-    << "  op = op;  // suppress warning\n"
+    << "  (void)op;  // suppress warning\n"
     << "  switch (opcode) {\n";
 
   // Emit each case statement