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

compiler/tests-java8/tests/org/jetbrains/kotlin/codegen/BlackBoxWithJava8CodegenTestGenerated.java

@@ -84,6 +84,12 @@ public class BlackBoxWithJava8CodegenTestGenerated extends AbstractBlackBoxCodeg
         doTest(fileName);
     }
 
+    @TestMetadata("functionAssertion.kt")
+    public void testFunctionAssertion() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/java8/box/functionAssertion.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("inheritKotlin.kt")
     public void testInheritKotlin() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/java8/box/inheritKotlin.kt");