Ant task: support "compilerarg" element in withKotlin as in kotlinc

compiler/testData/integration/ant/jvm/additionalArguments/build.log.expected

@@ -3,6 +3,10 @@ Buildfile: [TestData]/build.xml
 
 build:
   [kotlinc] Compiling [[TestData]/hello.kt] => [[Temp]/hello.jar]
+    [javac] Compiling 1 source file to [Temp]
+    [javac] Compiling [[TestData]] => [[Temp]]
+    [javac] INFO: Kotlin Compiler version [KotlinVersion]
+    [javac] Running javac...
 
 BUILD SUCCESSFUL
 Total time: [time]

compiler/testData/integration/ant/jvm/additionalArguments/build.xml

@@ -7,5 +7,11 @@
             <compilerarg line="-Xno-call-assertions -Xno-param-assertions"/>
             <compilerarg value="-Xno-optimize"/>
         </kotlinc>
+
+        <javac srcdir="${test.data}" destdir="${temp}" includeantruntime="false">
+            <withKotlin>
+                <compilerarg value="-version"/>
+            </withKotlin>
+        </javac>
     </target>
 </project>