Disable field assignments in record compact constructors

Last piece of IDEA-239088

GitOrigin-RevId: 23c467c6c525d7908922bc2ebd8928205368dff7

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlightingRecords/RecordCompactConstructorsJava15.java

@@ -0,0 +1,8 @@
+record WrittenFields(int x, 
+                     int y, 
+                     int z) {
+  public WrittenFields {
+    <error descr="Cannot assign a value to final variable 'x'">this.x</error> = 0;
+    if (Math.random() > 0.5) <error descr="Cannot assign a value to final variable 'y'">this.y</error> = 1;
+  }
+}