[TEST_BUG]: JDK-8214799 11u backport broke gc/CriticalNativeStress.java and gc/CriticalNativeArgs.java

When 11u build includes Shenandoah GC. Tests test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeArgs.java and test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeStress.java fail with UnsatisfiedLinkError. This happens because the backport of https://bugs.openjdk.org/browse/JDK-8214799 to 11u misses the following changes:

diff --git a/test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeArgs.java b/test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeArgs.java
index fca66ae07f..2e861b0f1c 100644
--- a/test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeArgs.java
+++ b/test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeArgs.java
@@ -37,20 +37,14 @@ package gc.shenandoah.jni;
  * @run main/othervm/native -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UnlockExperimentalVMOptions -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive -Xcomp -Xmx51
2M -XX:+CriticalJNINatives gc.shenandoah.jni.CriticalNativeArgs
  */
 public class CriticalNativeArgs {
- static {
- System.loadLibrary("CriticalNative");
- }
-
- static native boolean isNull(int[] a);
-
     public static void main(String[] args) {
         int[] arr = new int[2];

- if (isNull(arr)) {
+ if (CriticalNative.isNull(arr)) {
             throw new RuntimeException("Should not be null");
         }

- if (!isNull(null)) {
+ if (!CriticalNative.isNull(null)) {
             throw new RuntimeException("Should be null");
         }
     }
diff --git a/test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeStress.java b/test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeStress.java
index bb559820ac..27ae22940a 100644
--- a/test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeStress.java
+++ b/test/hotspot/jtreg/gc/shenandoah/jni/CriticalNativeStress.java
@@ -30,7 +30,7 @@ import gc.shenandoah.jni.CriticalNative;

 /* @test
  * @key randomness
- * @library /test/lib
+ * @library /test/lib /
  * @requires (os.arch =="x86_64" | os.arch == "amd64" | os.arch=="x86" | os.arch=="i386") & !vm.graal.enabled & vm.gc.Shenandoah
  *
  * @run main/othervm/native -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive -XX:+ShenandoahDegeneratedGC -Xcomp -Xmx512M -XX:+CriticalJNINatives gc.shenandoah.jni.CriticalNativeStress
@@ -43,18 +43,9 @@ import gc.shenandoah.jni.CriticalNative;
  * @run main/othervm/native -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive -Xcomp -Xmx512M -XX:+CriticalJNINatives gc.shenandoah.jni.CriticalNativeStress
  */
 public class CriticalNativeStress {
- static {
- System.loadLibrary("CriticalNative");
- }
-
     static final int CYCLES = 50;
     static final int THREAD_PER_CASE = 1;

- static native long sum1(long[] a);
-
- // More than 6 parameters
- static native long sum2(long a1, int[] a2, int[] a3, long[] a4, int[] a5);
-
     static long sum(long[] a) {
         long sum = 0;
         for (int index = 0; index < a.length; index++) {
@@ -93,7 +84,7 @@ public class CriticalNativeStress {
             create_garbage(index);
         }

- long native_sum = sum1(arr);
+ long native_sum = CriticalNative.sum1(arr);
         long java_sum = sum(arr);
         if (native_sum != java_sum) {
             StringBuffer sb = new StringBuffer("Sums do not match: native = ")
@@ -135,7 +126,7 @@ public class CriticalNativeStress {
             create_garbage(index);
         }

- long native_sum = sum2(a1, a2, a3, a4, a5);
+ long native_sum = CriticalNative.sum2(a1, a2, a3, a4, a5);
         long java_sum = a1 + sum(a2) + sum(a3) + sum(a4) + sum(a5);
         if (native_sum != java_sum) {
             StringBuffer sb = new StringBuffer("Sums do not match: native = ")