Remove KotlinSignature from tests, spec, delete tests with errors

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

@@ -1,11 +1,8 @@
 package test;
 
-import jet.runtime.typeinfo.KotlinSignature;
-
 import java.io.Serializable;
 
 public class AllBoundsInWhen {
-    @KotlinSignature("fun <T> foo() where T: Serializable")
     public <T extends Serializable> void foo() {
         throw new UnsupportedOperationException();
     }