Add comment that explains purpose of SquashedParts record

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/resources/CompressedGlobTrie/CompressedGlobTrie.java

@@ -46,9 +46,22 @@ public class CompressedGlobTrie {
  public record GlobWithInfo(String pattern, String additionalContent) {
  }
 
+ /*
+ * Data transfer object that points to the next matched child instance and its index in the
+ * pattern parts list
+ */
  private record MatchedNode(GlobTrieNode child, int lastMatchedChildIndex) {
  }
 
+ /*
+ * In case we have a complex level like: .../bar*Test*set/... its representation in the trie
+ * will be: bar* -> Test* -> set; In order to find all the nodes (on the same level) we need to
+ * squash them and return the number of squashed parts. Example: foo/bar*Test*set/1.txt pattern
+ * will be transformed into the following list of parts: [foo, bar*, Test*, set, 1.txt] in the
+ * first phase of the algorithm. Based on this list we don't know where the level, which starts
+ * with bar*, ends. To figure that out, we call a helper function which returns bar*Test*set and
+ * the number 3 because it squashed "bar*", "Test*" and "set" into one part.
+ */
  private record SquashedParts(String squashedPart, int numberOfSquashedParts) {
  }