title: BigQuery producing negative (!) zero when numeric 0.0 multiplied with negative numerics/integers
body: <p>I intend to do a CSV export directly from BigQuery, using the bq CLI (with flag <code>--format=csv</code>). I run into an issue where if a column with a numeric value is multiplied with a negative one, BigQuery returns <code>-0.0</code> (whatever that means) and this causes issues in the importing system of this CSV file.</p>
  <p>Example:</p>
  <pre><code>&gt; SELECT (0.0 * -1) AS result;
  Row result  
  1   -0.0
  </code></pre>
  <p>How can get I this result in <code>0.0</code> instead (of course the numeric value 0.0 will in most cases not be 0.0)? Is this a bug in BigQuery?</p>