[modules] Make @@toStringTag on namespace objects non-configurable.

test/test262/test262.status

 # Copyright 2011 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 401 matching lines @@
   'language/module-code/namespace/internals/define-own-property': [FAIL],
 
   # Symbol.iterator on namespace objects was removed, tests need to be updated.
   'language/module-code/namespace/Symbol.iterator/*': [SKIP],
   'language/module-code/namespace/internals/get-own-property-sym': [SKIP],
   'language/module-code/namespace/internals/get-sym-found': [SKIP],
   'language/module-code/namespace/internals/has-property-sym-found': [SKIP],
   'language/module-code/namespace/internals/own-property-keys-binding-types': [SKIP],
   'language/module-code/namespace/internals/own-property-keys-sort': [SKIP],
 
+  # Symbol.toString on namespace objects was made non-configurable, tests need
+  # to be updated.
+  'language/module-code/namespace/Symbol.toStringTag': [SKIP],
+
+  # Possible spec bug, see comment in https://github.com/tc39/ecma262/pull/747.
+  'language/module-code/namespace/internals/delete-non-exported': [SKIP],
+
 ######################## NEEDS INVESTIGATION ###########################
 
   # These test failures are specific to the intl402 suite and need investigation
   # to be either marked as bugs with issues filed for them or as deliberate
   # incompatibilities if the test cases turn out to be broken or ambiguous.
   # Some of these are related to v8:4361 in being visible side effects from Intl.
   'intl402/6.2.3': [FAIL],
   'intl402/Collator/10.1.2.1_4': [FAIL],
   'intl402/Collator/10.1.2_a': [PASS, FAIL],
   'intl402/Collator/10.2.3_b': [PASS, FAIL],
@@ skipping 140 matching lines @@
 
 ['variant == asm_wasm', {
   '*': [SKIP],
 }],  # variant == asm_wasm
 
 ['variant == wasm_traps', {
   '*': [SKIP],
 }],  # variant == wasm_traps
 
 ]