[clang] [clang-format] Google Style: disable DerivePointerAlignment. (PR #149602)

[Owen Pan via cfe-commits]

owenca wrote:

> Style Guide has been updated internally. I don't know how long it takes to make its way to the public site, so I'd like to proceed. I've pasted the updated text into the commit description above.

I still think we should wait until it becomes official. WDYT @mydeveloperday @AaronBallman ?

https://github.com/llvm/llvm-project/pull/149602