[MLIR] NFC: fully scope use FastMathFlag.

Author: chsigg

mlir/include/mlir/Dialect/Arith/IR/ArithOps.td

@@ -69,7 +69,8 @@ class Arith_FloatUnaryOp<string mnemonic, list<Trait> traits = []> :
       !listconcat([DeclareOpInterfaceMethods<ArithFastMathInterface>],
                   traits)>,
     Arguments<(ins FloatLike:$operand,
-      DefaultValuedAttr<Arith_FastMathAttr, "FastMathFlags::none">:$fastmath)>,
+      DefaultValuedAttr<
+        Arith_FastMathAttr, "::mlir::arith::FastMathFlags::none">:$fastmath)>,
     Results<(outs FloatLike:$result)> {
   let assemblyFormat = [{ $operand (`fastmath` `` $fastmath^)?
                           attr-dict `:` type($result) }];