Get rid of redundant not-null assertion for parameter

The problem was that in `Function<T>.apply(T)` T is now not-platform,
so when checking if not-null assertion is needed for parameter in SAM,
it's defined by the upper bounds of T that is a platform (Any..Any?),
and while it's definitely not marked as nullable it's still nullable
in a sense that it can contain null as a value.

So the solution is obvious

 #KT-16413 Fixed

core/descriptors/src/org/jetbrains/kotlin/types/TypeUtils.java

@@ -304,8 +304,7 @@ public class TypeUtils {
         }
 
         for (KotlinType supertype : getImmediateSupertypes(type)) {
-            if (supertype.isMarkedNullable()) return true;
-            if (hasNullableSuperType(supertype)) return true;
+            if (isNullableType(supertype)) return true;
         }
 
         return false;