javac-wrapper: refactoring, fixes and tests

compiler/testData/diagnostics/tests/functionLiterals/kt11733_1.kt

@@ -1,7 +1,7 @@
 // !CHECK_TYPE
 
 // FILE: Predicate.java
-import org.jetbrains.annotations.NotNull
+import org.jetbrains.annotations.NotNull;
 
 public interface Predicate<T extends CharSequence> {
     // Same effect with @Nullable here
@@ -13,4 +13,4 @@ fun main(args: Array<String>) {
     process(Predicate { x -> x checkType { _<String>() }
         true
     })
-}
+}