code: Symbol resolveBinaryOperator(DiagnosticPosition pos,
                                   JCTree.Tag optag,
                                   Env<AttrContext> env,
                                   Type left,
                                   Type right) {
          return resolveOperator(pos, optag, env, List.of(left, right));
      }
docs: Resolve binary operator.
  @param pos       The position to use for error reporting.
  @param optag     The tag of the operation tree.
  @param env       The environment current at the operation.
  @param left      The types of the left operand.
  @param right     The types of the right operand.