[clang] [AArch64][PAC] Emit `!dbg` locations in `*_vfpthunk_` functions (PR #179688)

[Anatoly Trosinenko via cfe-commits]

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atrosinenko wrote:

Updated the description to clarify that these are not "two options" how things can go wrong, these are "two points in time" at which the issue can be caught. And this test case validates at the third (or, better, the zeroth) point in time that actually results in the verifier error after an indirect call gets replaced with a direct one :)

https://github.com/llvm/llvm-project/pull/179688