[ASTERIXDB-2689][FUN] Make numeric functions return NULL on invalid arguments p2

- user model changes: no
- storage format changes: no
- interface changes: no

Details:
Make numeric functions return NULL on invalid arguments.
round(num), round(num, num), trunc(num, num), round-half-to-even(num, num).

- added warning to round() function
- extracted evaluators of trunc() and round-half-to-even() to a common evaluator
- renamed checkWarnOrSetInteger() to setInteger()

Change-Id: I1ccef0740d64cce3ada8b60d3a699748e7ef8776
Reviewed-on: https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/4704
Contrib: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Ali Alsuliman <ali.al.solaiman@gmail.com>
Reviewed-by: Dmitry Lychagin <dmitry.lychagin@couchbase.com>
diff --git a/asterixdb/asterix-app/src/test/resources/runtimets/testsuite_sqlpp.xml b/asterixdb/asterix-app/src/test/resources/runtimets/testsuite_sqlpp.xml
index e81c6a3..c4c5e8f 100644
--- a/asterixdb/asterix-app/src/test/resources/runtimets/testsuite_sqlpp.xml
+++ b/asterixdb/asterix-app/src/test/resources/runtimets/testsuite_sqlpp.xml
@@ -13819,5 +13819,31 @@
         <source-location>false</source-location>
       </compilation-unit>
     </test-case>
+    <test-case FilePath="fun_return_null/numeric_fun" check-warnings="true">
+      <compilation-unit name="numeric_fun_002">
+        <output-dir compare="Text">numeric_fun_002</output-dir>
+        <expected-warn>Type mismatch: function round expects its 1st input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round-half-to-even expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function trunc expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round-half-to-even expects its 1st input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function trunc expects its 1st input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round expects its 2nd input parameter to be of type tinyint, smallint, integer or bigint, but the actual input type is string</expected-warn>
+
+        <expected-warn>Type mismatch: function round expects its 1st input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round-half-to-even expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function trunc expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round expects its 1st input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round-half-to-even expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function trunc expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+
+        <expected-warn>Type mismatch: function round expects its 1st input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round-half-to-even expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function trunc expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round expects its 1st input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function round-half-to-even expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <expected-warn>Type mismatch: function trunc expects its 2nd input parameter to be of type tinyint, smallint, integer, bigint, float or double, but the actual input type is string</expected-warn>
+        <source-location>false</source-location>
+      </compilation-unit>
+    </test-case>
   </test-group>
 </test-suite>