[clang] [NFC] Use `const&` avoiding copies (PR #90334)

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lipracer wrote:

This change seems to be unrelated to the platform, and I don't think it's the change that caused the CI error. From the compiled log, it seems that there is not enough memory space.
<img width="1499" alt="3eb6d694feb6b9b289d0fff72552fb88" src="https://github.com/llvm/llvm-project/assets/22370779/d1acbd6b-45e4-46c0-b297-9d0a8f8abedb">


https://github.com/llvm/llvm-project/pull/90334