LUCENE-7767: SortedDocValues.ordValue() now throws an IOException.

lucene/core/src/java/org/apache/lucene/index/MultiDocValues.java

@@ -1031,7 +1031,7 @@ public class MultiDocValues {
     }
     
     @Override
-    public int ordValue() {
+    public int ordValue() throws IOException {
       return (int) mapping.getGlobalOrds(nextLeaf-1).get(currentValues.ordValue());
     }
  

lucene/core/src/java/org/apache/lucene/index/SortedDocValues.java

@@ -46,7 +46,7 @@ public abstract class SortedDocValues extends BinaryDocValues {
    * @return ordinal for the document: this is dense, starts at 0, then
    *         increments by 1 for the next value in sorted order.
    */
-  public abstract int ordValue();
+  public abstract int ordValue() throws IOException;
 
   /** Retrieves the value for the specified ordinal. The returned
    * {@link BytesRef} may be re-used across calls to {@link #lookupOrd(int)}

lucene/misc/src/test/org/apache/lucene/search/TestDiversifiedTopDocsCollector.java

@@ -154,7 +154,7 @@ public class TestDiversifiedTopDocsCollector extends LuceneTestCase {
         }
         
         @Override
-        public long longValue() {
+        public long longValue() throws IOException {
           // Keys are always expressed as a long so we obtain the
           // ordinal for our String-based artist name here
           return sdv.ordValue();

lucene/test-framework/src/java/org/apache/lucene/index/AssertingLeafReader.java

@@ -630,7 +630,7 @@ public class AssertingLeafReader extends FilterLeafReader {
     }
 
     @Override
-    public int ordValue() {
+    public int ordValue() throws IOException {
       assertThread("Sorted doc values", creationThread);
       assert exists;
       int ord = in.ordValue();