[java-decompiler] IJ-CR-118414 IDEA-326015 Support instanceOf decons…

…truction

GitOrigin-RevId: 863d4cb5ba61a43b8dfc91bd3b4788c5c8d5d01e

src/org/jetbrains/java/decompiler/modules/decompiler/PatternHelper.java

@@ -46,6 +46,11 @@ public static void replaceAssignmentsWithPatternVariables(@NotNull RootStatement
     removeTempVariableDeclarations(tempVarAssignments);
   }
 
+  /**
+   * Replaces assignments with pattern variables in the provided statement.
+   *
+   * @return a list of Runnable objects containing the actions to replace assignments with pattern variables
+   */
   private static List<Runnable> replaceAssignmentsWithPatternVariables(@NotNull Statement statement,
                                                              @NotNull List<TempVarAssignmentItem> tempVarAssignments,
                                                              boolean recordPatternSupport,

src/org/jetbrains/java/decompiler/modules/decompiler/exps/RecordVarExprent.java

@@ -62,9 +62,13 @@ public RecordVarExprent copy() {
   }
 
   /**
-   * @return a copy of the current RecordVarExprent object, including a copy of its VarExprent superclass, excluding components
+   * Copies the values from the provided VarExprent object to the current RecordVarExprent object.
+   * If the provided VarExprent object is an instance of RecordVarExprent, copies the components from it.
+   * Otherwise, copy the varType, index, and version from the provided VarExprent object.
+   *
+   * @param varExprent the VarExprent object to copy the values from
+   * @return true if the copying is successful (the current set of components is empty), false otherwise
    */
-
   public boolean copyFrom(@NotNull VarExprent varExprent) {
     if (varExprent instanceof RecordVarExprent recordVarExprent) {
       if (!this.components.isEmpty()) {