Remove KotlinSignature from tests, spec, delete tests with errors

compiler/testData/loadJava/compiledJava/kotlinSignature/MethodWithMappedClasses.java

@@ -1,11 +1,8 @@
 package test;
 
-import java.lang.UnsupportedOperationException;
 import java.util.*;
-import jet.runtime.typeinfo.KotlinSignature;
 
 public class MethodWithMappedClasses {
-    @KotlinSignature("fun <T> copy(dest : MutableList<in T>, src : List<T>)")
     public <T> void copy(List<? super T> dest, List<T> src) {
         throw new UnsupportedOperationException();
     }