Update doc and add one more test case

Author: WangGuangxin

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/RewriteArithmeticFiltersOnIntOrLongColumn.scala

@@ -38,6 +38,9 @@ import org.apache.spark.sql.types.{DataType, IntegerType, LongType}
  * {{{
  *   SELECT * FROM table WHERE i = 2
  * }}}
+ * The arithmetic operation supports `Add` and `Subtract`. The comparision supports
+ * '=', '>=', '<=', '>', '<', '!='. It only supports type of `INT` and `LONG`,
+ * it doesn't support `FLOAT` or `DOUBLE` for precision issues.
  */
 object RewriteArithmeticFiltersOnIntOrLongColumn extends Rule[LogicalPlan] with PredicateHelper {
   def apply(plan: LogicalPlan): LogicalPlan = plan transform {

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/RewriteArithmeticFiltersOnIntOrLongColumnSuite.scala

@@ -240,4 +240,15 @@ class RewriteArithmeticFiltersOnIntOrLongColumnSuite extends PlanTest {
 
     comparePlans(Optimize.execute(query.analyze), correctAnswer)
   }
+
+  test("test of int: 2 - a != 8") {
+    val query = testRelation
+      .where(Subtract(Literal(2), columnA) != Literal(8))
+
+    val correctAnswer = testRelation
+      .where(Literal(-6) != columnA)
+      .analyze
+
+    comparePlans(Optimize.execute(query.analyze), correctAnswer)
+  }
 }