Don't reuse other descriptor's value parameters

This resulted in a rewrite at INDEX_FOR_VALUE_PARAMETER slice, since some value
parameters were found twice in different function descriptors

core/descriptors/src/org/jetbrains/jet/lang/descriptors/ValueParameterDescriptor.java

@@ -57,7 +57,7 @@ public interface ValueParameterDescriptor extends VariableDescriptor {
     ValueParameterDescriptor getOriginal();
 
     @NotNull
-    ValueParameterDescriptor copy(DeclarationDescriptor newOwner, Name newName);
+    ValueParameterDescriptor copy(@NotNull DeclarationDescriptor newOwner, @NotNull Name newName);
 
     /**
      * Parameter p1 overrides p2 iff