[clang] [clang] Fix sema on ObjCLifetime conversion (PR #178524)

[Oliver Hunt via cfe-commits]

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ojhunt wrote:

I think these should be renamed now, and as a minor nit the `auto` should be replaced with `Qualifiers` according to style rules. Obviously this code does have some exciting variations on the code style, but if we're changing these lines for the naming we may as well correct the type specifiers.

https://github.com/llvm/llvm-project/pull/178524