[release/8.0] Enable output compilation validation in binder gen unit tests

[github-actions]

Backport of #91565 to release/8.0

Customer Impact

Fixes an RC-2 regression introduced in #91359, where any compilation that has binding IServiceCollection.Configure invocations fails if it has no OptionsBuilder.Bind[Configuration] invocations.

---

this fails because we reference options APIs without emitting the needed namespace

ConfigurationBuilder configurationBuilder = new();
IConfiguration config = configurationBuilder.Build();
IConfigurationSection section = config.GetSection("MySection");

ServiceCollection services = new();
services.Configure<MyClass>({{paramList}});

this passes because the needed namespace is emitted due to intercepting options builder invocation

ServiceCollection services = new();
services.Configure<MyClass>({{paramList}});

OptionsBuilder<MyClass> optionsBuilder = new(services, Options.DefaultName);
optionsBuilder.BindConfiguration(""{{configureActions}});

Testing

We had tests that covered the regressed case, but we were only comparing the compiler output and not actually compiling it. This change makes sure we compile all the baselines and either assert that they are clean or only contain expected diagnostics.

Improves unit tests by examining final compilation in addition to the intermediate compilation after running the generator. This will prevent generator iterative changes from regressing successful compilation for any of the emitted interceptors.

The reinforced Configure overload baseline tests verify that the regression has been fixed.

Risk

Low.

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Issue Details

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Backport of #91565 to release/8.0

/cc @layomia

Customer Impact

Testing

Risk

IMPORTANT: If this backport is for a servicing release, please verify that:

• The PR target branch is release/X.0-staging, not release/X.0.

• If the change touches code that ships in a NuGet package, you have added the necessary package authoring and gotten it explicitly reviewed.

Author:	github-actions[bot]
Assignees:	-
Labels:	area-Extensions-Configuration
Milestone:	-

[artl93]

M2 approved.