Work around a bogus gcc 4.2 warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39993 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/AsmWriterEmitter.cpp

@@ -28,7 +28,8 @@ static bool isIdentChar(char C) {
          C == '_';
 }
 
-namespace {
+// This should be an anon namespace, this works around a GCC warning.
+namespace llvm {  
   struct AsmWriterOperand {
     enum { isLiteralTextOperand, isMachineInstrOperand } OperandType;