Better detect when typical nondistributive conditionals need to be deferred... #42248
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…fered by unwrapping their check and extends types
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…fered by unwrapping their check and extends types (microsoft#42248)
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…by unwrapping their check and extends types. We use a heuristic for conditional type deferral - our
isGenericObjectTypeandisGenericIndexTypehelpers. Unfortunately, these aren't tuned to check for nested generics within types, such as tuples, as we often see for non-distributive conditional types. Rather than changing those functions (where are used elsewhere), instead I detect when a conditional type has a typical non-distributive shape (one-tuple extends one-tuple), and immediately unwrap the tuple types - this both saves us a bit of work, and allows the deferral checks to operate like we want.Fixes #39992