In methods, we load the field with FieldLoadOp.
In lambdas, we refer to the (constant) value of the field.
Here's an example:

static final int Z = 42;

    /*
    func @"f" (%0 : java.type:"int")java.type:"int" -> {
      %1 : Var<java.type:"int"> = var %0 @"i";
      %2 : java.type:"int" = field.load @java.ref:"TestAST::Z:int";
      return %2;
    };
    */
    @CodeReflection
    static int f(int i) {
        return Z;
    }

    /*
    func @"quotedLambda" ()java.type:"jdk.incubator.code.Quoted" -> {
      %0 : java.type:"int" = constant @42;
      %1 : Var<java.type:"int"> = var %0 @"Z";
      %2 : java.type:"jdk.incubator.code.Quoted" = quoted ()java.type:"void" -> {
          %3 : java.type:"TestAST$QRunnable" = lambda ()java.type:"void" -> {
              %4 : java.type:"int" = var.load %1;
              %5 : Var<java.type:"int"> = var %4 @"x";
              return;
          };
          yield %3;
      };
      return %2;
    };
    */
    QRunnable qr = () -> {
        int x = Z;
    };