[windows] Adapt test to pass on Windows.

[drodriguez]

The underscores weren't printed while compiling for Windows between the
symbolic and the mangled name tokens. Make the underscores optional, to
allow the test pass on Windows.

This should fix the failing test on Windows.

I am not sure this is the right fix. I am just uploading in order to find out the best way. I don't understand what those underscores mean, but since they were added in 3ca0859, I imagine they are important. I reviewed the code of #27666, and I don't obviously see where the difference in Windows might come from or what those underscores actually mean. Any alternative solution would be greatly appreciated.

[drodriguez]

(this might fail with the Error 87 I am trying to figure out, but reading the logs will let me know if the test also passes in CI or not)

@swift-ci please test Windows platform

[drodriguez]

No failure in the test themselves, still seeing the unexplained WindowsError: [Error 87] The parameter is incorrect.

@swift-ci please smoke test

[jckarter]

If you're feeling more ambitious, it'd be great to implement PE support for loading relocated pointers from the import table to ObjectMemoryReader in swift-reflection-dump, which would eliminate the root cause of the divergence here.

[drodriguez]

I am going to merge this version for the time being, in order to have a green on Windows again. I will try to talk with @alexshap later and try to figure out the alternative approach.

[jckarter]

SGTM, you should definitely commit this to keep the builds green, I was just suggesting a good follow-up Windows quality-of-implementation task.