[clang] [clang][Diagnostics] Fix wrong line number display (PR #65238)

[Timm Baeder via cfe-commits]

tbaederr wrote:

In 8554a55d041f2c7de329adda538cadf7eeb6e8a8, this was added to fix a range with a lower begin source location than `Loc` is, so I think this change would break that?

https://github.com/llvm/llvm-project/pull/65238