Start on [CALCITE-1258] JDK9 support

Tried to upgrade plexus-archiver to get fix for
codehaus-plexus/plexus-archiver#12
but maven doesn't seem to be seeing it yet.

Author: julianhyde

pom.xml

@@ -511,10 +511,10 @@ limitations under the License.
             <id>validate</id>
             <phase>validate</phase>
             <configuration>
-              <configLocation>${top.dir}/src/main/config/checkstyle/checker.xml</configLocation>
-              <suppressionsLocation>${top.dir}/src/main/config/checkstyle/suppressions.xml</suppressionsLocation>
+              <configLocation>file:${top.dir}/src/main/config/checkstyle/checker.xml</configLocation>
+              <suppressionsLocation>file:${top.dir}/src/main/config/checkstyle/suppressions.xml</suppressionsLocation>
               <consoleOutput>true</consoleOutput>
-              <headerLocation>${top.dir}/src/main/config/checkstyle/header.txt</headerLocation>
+              <headerLocation>file:${top.dir}/src/main/config/checkstyle/header.txt</headerLocation>
               <failOnViolation>true</failOnViolation>
               <includeTestSourceDirectory>true</includeTestSourceDirectory>
             </configuration>
@@ -662,6 +662,28 @@ limitations under the License.
           <artifactId>checksum-maven-plugin</artifactId>
           <version>${checksum-maven-plugin.version}</version>
         </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-assembly-plugin</artifactId>
+          <dependencies>
+            <dependency>
+              <groupId>org.codehaus.plexus</groupId>
+              <artifactId>plexus-archiver</artifactId>
+                <version>3.0.3</version>
+            </dependency>
+          </dependencies>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-jar-plugin</artifactId>
+          <dependencies>
+            <dependency>
+              <groupId>org.codehaus.plexus</groupId>
+              <artifactId>plexus-archiver</artifactId>
+                <version>3.0.3</version>
+            </dependency>
+          </dependencies>
+        </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-checkstyle-plugin</artifactId>