[SPARK-18993][BUILD] Unable to build/compile Spark in IntelliJ due to missing...

[SPARK-18993][BUILD] Unable to build/compile Spark in IntelliJ due to missing Scala deps in spark-tags

## What changes were proposed in this pull request?

This adds back a direct dependency on Scala library classes from spark-tags because its Scala annotations need them.

## How was this patch tested?

Existing tests

Author: Sean Owen <sowen@cloudera.com>

Closes #16418 from srowen/SPARK-18993.

common/tags/pom.xml

@@ -34,6 +34,14 @@
     <sbt.project.name>tags</sbt.project.name>
   </properties>
 
+  <dependencies>
+    <dependency>
+      <groupId>org.scala-lang</groupId>
+      <artifactId>scala-library</artifactId>
+      <version>${scala.version}</version>
+    </dependency>
+  </dependencies>
+
   <build>
     <outputDirectory>target/scala-${scala.binary.version}/classes</outputDirectory>
     <testOutputDirectory>target/scala-${scala.binary.version}/test-classes</testOutputDirectory>