[C Data] JNI release callback calls void PrivateData.close() with CallObjectMethod #1385

Describe the bug, including details regarding any error messages, version, and platform.

Disclaimer: Claude Opus 5 found this bug.

Describe the bug

In c/src/main/cpp/jni_wrapper.cc, the release callbacks of exported arrays/schemas
(release_exported) and of exported array streams call PrivateData.close() with
CallObjectMethod. That method is void (its ID is looked up with signature "()V"), and the JNI
specification requires the Call<type>Method matching the return type, i.e. CallVoidMethod:

kPrivateDataCloseMethod = GetMethodID(env, kPrivateDataClass, "close", "()V");
...
env->CallObjectMethod(private_data->j_private_data_, kPrivateDataCloseMethod);  // lines 173 and 298 at v19.0.0

HotSpot's -Xcheck:jni does not notice, but OpenJ9 (IBM Semeru) with -Xcheck:jni aborts the JVM
whenever an exported array, schema or stream is released, which happens whenever a native consumer
of the C Data Interface finishes with data exported from Java. We hit it with a Rust library that
imports batches exported with Data.exportVectorSchemaRoot and drops them.

To reproduce

import org.apache.arrow.c.ArrowArray;
import org.apache.arrow.c.ArrowSchema;
import org.apache.arrow.c.Data;
import org.apache.arrow.memory.BufferAllocator;
import org.apache.arrow.memory.RootAllocator;
import org.apache.arrow.vector.IntVector;

public class ReleaseRepro {
    public static void main(String[] args) {
        try (BufferAllocator allocator = new RootAllocator();
             IntVector v = new IntVector("x", allocator);
             ArrowArray array = ArrowArray.allocateNew(allocator);
             ArrowSchema schema = ArrowSchema.allocateNew(allocator)) {
            v.allocateNew(1);
            v.set(0, 1);
            v.setValueCount(1);
            Data.exportVector(allocator, v, null, array, schema);
            array.release();   // calls the exported struct's release callback
            schema.release();
        }
        System.out.println("done");
    }
}

Run on IBM Semeru 21.0.10+7 (OpenJ9 0.57.0) with arrow-c-data 19.0.0:

java -Xcheck:jni --add-opens=java.base/java.nio=ALL-UNNAMED -cp ... ReleaseRepro
JVMJNCK001I JNI check utility installed. Use -Xcheck:jni:help for usage
JVMJNCK046E JNI error in CallObjectMethod/CallObjectMethodV: Method has wrong return type ('V')
JVMJNCK077E Error detected in org/apache/arrow/c/jni/JniWrapper.releaseArray(J)V

JVMJNCK024E JNI error detected. Aborting.
JVMJNCK025I Use -Xcheck:jni:nonfatal to continue running when errors are detected.

Fatal error: JNI error

On HotSpot 21 the same program prints done.

Expected behavior

No JNI check error: both calls of close() in jni_wrapper.cc use CallVoidMethod. Present at
v19.0.0 and unchanged on main.

Component(s)

Java (arrow-c-data 19.0.0)