[clang] [-Wunsafe-buffer-usage] Fix false negatives of missing 2-param span ctors in constructor initializers (PR #113226)

[Artem Dergachev via cfe-commits]

haoNoQ wrote:

This overlaps with #91991 which should probably be landed in its entirety. (It looks like it's about attributes but in fact it isn't. It's about finding *all* gadgets in all those new places.) I think that patch was almost ready and it was a matter of considering my fix in https://github.com/llvm/llvm-project/pull/91991#discussion_r1643433741

https://github.com/llvm/llvm-project/pull/113226