Remove KotlinSignature annotations from project code

compiler/testData/codegen/notNullAssertions/A.java

@@ -1,4 +1,3 @@
-import jet.runtime.typeinfo.KotlinSignature;
 import org.jetbrains.annotations.NotNull;
 
 public class A {
@@ -8,27 +7,22 @@ public class A {
     @NotNull
     public static final String STATIC_NULL = null;
     
-    @KotlinSignature("fun foo() : String")
     public String foo() {
         return null;
     }
     
-    @KotlinSignature("fun staticFoo() : String")
     public static String staticFoo() {
         return null;
     }
     
-    @KotlinSignature("fun plus(a: A) : A")
     public A plus(A a) {
         return null;
     }
 
-    @KotlinSignature("fun inc() : A")
     public A inc() {
         return null;
     }
     
-    @KotlinSignature("fun get(o: Any) : Any")
     public Object get(Object o) {
         return null;
     }