[Bug]: don't overwrite explicit access with calculated access

[jhendrixMSFT]

Describe the bug

If a type has explicitly set @@access, that value shouldn't be overwritten by a calculated value.

Reproduction

For the following tsp, I expect that BaseClassThatsPruned should have its access set to internal. However, it's set to public.

import "@azure-tools/typespec-client-generator-core";

using Azure.ClientGenerator.Core;

@service({
  title: "ModelsOnly",
})
namespace ModelsOnly;

model BaseClassThatsPruned {
    id: int32;
}

model DerivedOne extends BaseClassThatsPruned {
    name: string;
}

model PreservedBaseClass {
    id: int32;
}

model DerivedTwo extends PreservedBaseClass {
    name: string;
}

@@access(ModelsOnly.BaseClassThatsPruned, Access.internal);
@@access(ModelsOnly.PreservedBaseClass, Access.public);
@@access(ModelsOnly.DerivedOne, Access.public);
@@access(ModelsOnly.DerivedTwo, Access.public);
@@usage(ModelsOnly.PreservedBaseClass, Usage.output);
@@usage(ModelsOnly.DerivedOne, Usage.output);
@@usage(ModelsOnly.DerivedTwo, Usage.output);

Checklist

• Follow our Code of Conduct
• Check that this issue is about the Azure libraries for typespec. For bug in the typespec language or core libraries file it in the TypeSpec repo
• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.

[tadelesh]

we do not allow override a model that needs to be public to internal currently. but it seems to be a reasonable for go scenario. i'd like to collect more thought for this. @Azure/dpg-devs

[weidongxu-microsoft]

Maybe this be language specific?

I guess Java won't compile pass, if BaseClassThatsPruned be not public/exported, but its subclass DerivedOne be public.

I am fine as long as user won't do this to Java... Unless they know what to follow up (with customization etc.) on this.