Make -betterC not disable EH, let -nothrow handle that

[ryuukk]

See #16174 for context

-nothrow was added recently, wich is what the user should use to disable EH, otherwise APIs like backtrace can't be used to generate stack traces, wich is useful for debugging

I added a change log entry, but my english might be poor, so please don't hesitate to rephrase it

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