GH-3493: Deprecate LittleEndianDataInputStream and migrate last test usage

After GH-3493 replaced the only production usage of LittleEndianDataInputStream
in PlainValuesReader with direct ByteBuffer reads, the class has no remaining
production callers. Mark it @deprecated and document the faster alternative.

Migrate the only remaining usage in TestColumnChunkPageWriteStore.intValue()
to ByteBuffer.getInt() with LITTLE_ENDIAN order, reading directly from
BytesInput.toByteBuffer() instead of round-tripping through a
ByteArrayOutputStream + ByteArrayInputStream + LittleEndianDataInputStream.

Per-call readInt() on the deprecated class performs 4 virtual in.read()
dispatches and manually reassembles the value with bit shifts. The
ByteBuffer.getInt() replacement is a HotSpot intrinsic that compiles to a
single unaligned load on x86/ARM.

The class is left in place (only @deprecated) for source/binary compatibility
of any downstream code that may still reference it. It can be removed in a
future major release.

All 308 parquet-common, 573 parquet-column, and TestColumnChunkPageWriteStore
column-order tests pass. (The two pre-existing JDK Hadoop getSubject failures
in TestColumnChunkPageWriteStore are unrelated to this change.)

Author: iemejia

parquet-common/src/main/java/org/apache/parquet/bytes/LittleEndianDataInputStream.java

@@ -21,10 +21,24 @@
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 
 /**
- * Based on DataInputStream but little endian and without the String/char methods
+ * Based on DataInputStream but little endian and without the String/char methods.
+ *
+ * @deprecated This class has no remaining production usages and is
+ *     significantly slower than reading directly from a {@link ByteBuffer} configured with
+ *     {@link ByteOrder#LITTLE_ENDIAN}. Each {@link #readInt()} performs four virtual
+ *     {@code in.read()} calls and reassembles the value with bit shifts, while
+ *     {@link ByteBuffer#getInt()} on a little-endian buffer is a HotSpot intrinsic that
+ *     compiles to a single unaligned load on x86/ARM. For new code, prefer
+ *     {@link ByteBufferInputStream#slice(int)} followed by
+ *     {@code buffer.order(ByteOrder.LITTLE_ENDIAN)} and {@link ByteBuffer#getInt()} /
+ *     {@link ByteBuffer#getLong()} / {@link ByteBuffer#getFloat()} /
+ *     {@link ByteBuffer#getDouble()}. This class will be removed in a future release.
  */
+@Deprecated
 public final class LittleEndianDataInputStream extends InputStream {
 
   private final InputStream in;

parquet-hadoop/src/test/java/org/apache/parquet/hadoop/TestColumnChunkPageWriteStore.java

@@ -38,9 +38,8 @@
 import static org.mockito.ArgumentMatchers.same;
 import static org.mockito.Mockito.inOrder;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.ByteOrder;
 import java.util.HashMap;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
@@ -49,7 +48,6 @@
 import org.apache.parquet.bytes.BytesInput;
 import org.apache.parquet.bytes.DirectByteBufferAllocator;
 import org.apache.parquet.bytes.HeapByteBufferAllocator;
-import org.apache.parquet.bytes.LittleEndianDataInputStream;
 import org.apache.parquet.bytes.TrackingByteBufferAllocator;
 import org.apache.parquet.column.ColumnDescriptor;
 import org.apache.parquet.column.Encoding;
@@ -249,12 +247,7 @@ public void test(Configuration config, ByteBufferAllocator allocator) throws Exc
   }
 
   private int intValue(BytesInput in) throws IOException {
-    ByteArrayOutputStream baos = new ByteArrayOutputStream();
-    in.writeAllTo(baos);
-    LittleEndianDataInputStream os = new LittleEndianDataInputStream(new ByteArrayInputStream(baos.toByteArray()));
-    int i = os.readInt();
-    os.close();
-    return i;
+    return in.toByteBuffer().order(ByteOrder.LITTLE_ENDIAN).getInt();
   }
 
   @Test