Don't assume that partitions with offset 0 are fillers.

(cherry picked from commit a9bbe92ec669adb1620152922209108637fd0bf5)

Author: christianhaeubl

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/ChunkedImageHeapAllocator.java

@@ -288,4 +288,9 @@ public String getName() {
     public long getSize() {
         throw VMError.shouldNotReachHereAtRuntime(); // ExcludeFromJacocoGeneratedReport
     }
+
+    @Override
+    public boolean isFiller() {
+        return true;
+    }
 }

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/ChunkedImageHeapPartition.java

@@ -186,6 +186,11 @@ public long getSize() {
         return getEndOffset() - getStartOffset();
     }
 
+    @Override
+    public boolean isFiller() {
+        return false;
+    }
+
     private static class SizeComparator implements Comparator<ImageHeapObject> {
         @Override
         public int compare(ImageHeapObject o1, ImageHeapObject o2) {

substratevm/src/com.oracle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/LinearImageHeapPartition.java

@@ -84,4 +84,9 @@ public long getEndOffset() {
     public long getSize() {
         return getEndOffset() - getStartOffset();
     }
+
+    @Override
+    public boolean isFiller() {
+        return false;
+    }
 }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/image/ImageHeapPartition.java

@@ -39,4 +39,7 @@ public interface ImageHeapPartition {
      * Returns the size of the partition (i.e., the sum of all allocated objects + some overhead).
      */
     long getSize();
+
+    /* Returns true if this partition is only used as a filler. */
+    boolean isFiller();
 }

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/image/NativeImageDebugInfoProvider.java

@@ -2700,7 +2700,7 @@ public long getSize() {
 
     private boolean acceptObjectInfo(ObjectInfo objectInfo) {
         /* This condition rejects filler partition objects. */
-        return (objectInfo.getPartition().getStartOffset() > 0);
+        return !objectInfo.getPartition().isFiller();
     }
 
     private DebugDataInfo createDebugDataInfo(ObjectInfo objectInfo) {