Remove KotlinSignature from tests, spec, delete tests with errors

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

@@ -1,11 +1,8 @@
 package test;
 
-import java.lang.UnsupportedOperationException;
 import java.util.*;
-import jet.runtime.typeinfo.KotlinSignature;
 
 public class MethodWithGenerics {
-    @KotlinSignature("fun foo(a : String, b : List<Entry<String?, String>?>) : String")
     public String foo(String a, List<Map.Entry<String, String>> b) {
         throw new UnsupportedOperationException();
     }