[clang] Symbol names on arm64 can have an extra char on front of name (PR #194937)

[via cfe-commits]

zeroomega wrote:

> @zeroomega can you try this change on mac. It fixes the aarch64 failure. I'll give it a try but, it would be nice to get your confirmation too. Thanks

I am doing a mac test run on this patch with task: https://ci.chromium.org/ui/p/fuchsia/builders/toolchain.ci.shadow/clang-host-mac-x64/b8683147853517890113/overview

https://github.com/llvm/llvm-project/pull/194937