JVM, JVM IR: Don't optimize null-checks based on nullability information

Since Java interop allows us to circumvent the Kotlin type system we
cannot rely on nullability information.

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -17920,6 +17920,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/platformTypes"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
         }
 
+        @TestMetadata("unsafeNullCheck.kt")
+        public void testUnsafeNullCheck() throws Exception {
+            runTest("compiler/testData/codegen/box/platformTypes/unsafeNullCheck.kt");
+        }
+
         @TestMetadata("compiler/testData/codegen/box/platformTypes/primitives")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)