[clang] [C2y] Support WG14 N3457, the __COUNTER__ macro (PR #162662)

[Aaron Ballman via cfe-commits]

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AaronBallman wrote:

You can't, the driver automagically handles that:

> `error: invalid integral value '-1' in '-finitial-counter-value=-1'`

https://github.com/llvm/llvm-project/pull/162662