j2k: flatten test cases and testData directory structure

Move j2k/test/tests -> j2k/tests, j2k/test/testData -> j2k/testData

j2k/testData/fileOrElement/annotations/jetbrainsNotNull.java

@@ -0,0 +1,32 @@
+// !forceNotNullTypes: false
+// !specifyLocalVariableTypeByDefault: true
+package test;
+
+import org.jetbrains.annotations.NotNull;
+
+public class Test {
+  @NotNull String myStr = "String2";
+
+  public Test(@NotNull String str) {
+    myStr = str;
+  }
+
+  public void sout(@NotNull String str) {
+    // UNNECESSARY_NOT_NULL_ASSERTION heuristic does not work any more, instead we can skip generating !! altogether
+    System.out.println(str);
+  }
+
+  @NotNull
+  public String dummy(@NotNull String str) {
+    return str;
+  }
+
+  public void test() {
+    sout("String");
+    @NotNull String test = "String2";
+    sout(test);
+    sout(dummy(test));
+
+    new Test(test);
+  }
+}