[clang] [clang] Allow devirtualisation of indirect calls to final virtual methods (PR #165341)

[Oliver Hunt via cfe-commits]

ojhunt wrote:

@ChuanqiXu9 I'm sure this will change codegen for existing tests so am running all of them atm, but I thought you should have a look at this.

https://github.com/llvm/llvm-project/pull/165341