Null pointer crash when loading module with unresolved import also as a script file

Null pointer crash when loading module with unresolved import also as a script file
https://bugs.webkit.org/show_bug.cgi?id=168971

Reviewed by Saam Barati.

JSTests:

* stress/re-execute-error-module.js: Added.
(shouldBe):
(async):
* stress/resources/error-module.js: Added.

Source/JavaScriptCore:

If linking throws an error, this error should be re-thrown
when requesting the same module.

* builtins/ModuleLoaderPrototype.js:
(globalPrivate.newRegistryEntry):
* runtime/JSModuleRecord.cpp:
(JSC::JSModuleRecord::link):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@213452 268f45cc-cd09-0410-ab3c-d52691b4dbfc