[clang-tools-extra] [clang-tidy] improve robustness of the member initializer detection in modernize-use-default-member-init (PR #159392)

[Baranov Victor via cfe-commits]

vbvictor wrote:

Could you add also test from https://github.com/llvm/llvm-project/issues/160394?

https://github.com/llvm/llvm-project/pull/159392