Do not expect specific error type in import-attributes/allow-nlt-before-with.js

[nicolo-ribaudo]

Hosts are free to throw whatever error they want during module loading: there is no guarantee that the error thrown due to the import with type: "foo" is a SyntaxError (it could also be, for example, an Error caused by a network failure). Technically this is also true when loading just JS, but not specifying type reduces variance and in practice all test262 runners will not fail when loading JS modules that exist :)

[ptomato]

Is my understanding here correct? Thinking of HTML hosts as an example, type is a supported import attribute, so the SyntaxError will not be thrown in InnerModuleLoading step 2.d.i.1. Instead a TypeError will be thrown in onSingleFetchComplete step 2, failing the test.
After this change, the TypeError in onSingleFetchComplete step 2 is not thrown, and instead the line import "./ensure-linking-error_FIXTURE.js"; throws the SyntaxError.

However, how do we distinguish between the SyntaxError from import "./ensure-linking-error_FIXTURE.js"; and the SyntaxError that would be thrown if the import declaration were instead parsed as an import declaration + with-statement, which would be a SyntaxError in module code?

[nicolo-ribaudo]

Is my understanding here correct? Thinking of HTML hosts as an example, type is a supported import attribute, so the SyntaxError will not be thrown in InnerModuleLoading step 2.d.i.1. Instead a TypeError will be thrown in onSingleFetchComplete step 2, failing the test.
After this change, the TypeError in onSingleFetchComplete step 2 is not thrown, and instead the line import "./ensure-linking-error_FIXTURE.js"; throws the SyntaxError.

This is all correct. Before this PR, hosts might throw an error due to the import attributes (either because they don't support type, or `

Before this PR, there where three possible cases:

• the host does not support the type attribute, so InnerModuleLoading throws a SyntaxError
• the host doesn't know how to handle that specific type, so it throws some error in HostLoadImporterModule
• loading works, so we ensure a SyntaxError error in ensure-linking-error_FIXTURE.js

This PR removes the first two cases, ensuring a consistent error.

If a host doesn't parse this properly, it would throw in the parse phase rather than in the resolution phase.

[ptomato]

OK.
I was going to ask, why don't we remove the ensure-linking-error_FIXTURE.js import, but then we don't actually have a way to say "this test is only for the parsing phase" other than causing an intentional error in the resolution phase. So, fine with me.