Move Null type to the Bottom in the VM (fixes #28025).

tests/language/language.status

Index: tests/language/language.status
diff --git a/tests/language/language.status b/tests/language/language.status
index 1571968819f0a47058b7b59a4c4d2391873041cd..ad08d6c1a39f0628c06a02b564b60b7dd8412a42 100644
--- a/tests/language/language.status
+++ b/tests/language/language.status
@@ -5,24 +5,12 @@
 # This directory contains tests that are intended to show the
 # current state of the language.
 
-[ $compiler == none || $compiler == app_jit ]
-null_is_bottom_test/22: RuntimeError # Issue 28025
-null_is_bottom_test/34: RuntimeError # Issue 28025
-
 [ $compiler == none || $compiler == precompiler || $compiler == app_jit ]
 # Tests that use the name#field tear off syntax which has been deprecated.
 tearoff_basic_test: CompileTimeError
 tearoff_constructor_basic_test: CompileTimeError
 # Other issues:
 generic_methods_type_expression_test: RuntimeError # Issue 25869
-null_is_bottom_test/05: RuntimeError # Issue 28025
-null_is_bottom_test/07: RuntimeError # Issue 28025
-null_is_bottom_test/20: RuntimeError # Issue 28025
-null_is_bottom_test/25: RuntimeError # Issue 28025
-null_is_bottom_test/27: RuntimeError # Issue 28025
-null_is_bottom_test/32: RuntimeError # Issue 28025
-null_is_bottom_test/37: RuntimeError # Issue 28025
-null_is_bottom_test/39: RuntimeError # Issue 28025
 
 # This is OK for now, but we may want to change the semantics to match the test.
 async_star_pause_test: Fail, OK
@@ -75,14 +63,8 @@ generic_methods_new_test: Pass # Issue 25869
 generic_local_functions_test: Pass # Issue 25869
 generic_functions_test: Pass # Issue 25869
 generic_methods_generic_function_parameter_test: Pass # Issue 25869
-null_is_bottom_test/03: RuntimeError # Issue 28025
-null_is_bottom_test/18: RuntimeError # Issue 28025
-null_is_bottom_test/23: RuntimeError # Issue 28025
-null_is_bottom_test/30: RuntimeError # Issue 28025
-null_is_bottom_test/35: RuntimeError # Issue 28025
 
 [ ($compiler == none || $compiler == precompiler || $compiler == app_jit) && ($runtime == vm || $runtime == dart_precompiled) ]
-
 class_keyword_test/02: MissingCompileTimeError # Issue 13627
 unicode_bom_test: Fail # Issue 16067
 vm/debug_break_enabled_vm_test/01: Crash, OK # Expected to hit breakpoint.