javac-wrapper: refactoring, fixes and tests

compiler/testData/diagnostics/tests/cast/checkCastToNullableType.kt

@@ -1,7 +1,7 @@
 // FILE: JavaClass.java
 
-import org.jetbrains.annotations.Nullable
-import org.jetbrains.annotations.NotNull
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.NotNull;
 
 public class JavaClass {
     static Integer foo() {
@@ -35,4 +35,4 @@ fun <T, S: Any> test(x1: T, x2: T?, y1: S, y2: S?) {
 
     val f3 = JavaClass.fooNN()
     <!USELESS_IS_CHECK!>f3 is Int<!USELESS_NULLABLE_CHECK!>?<!><!>
-}
+}