[clang] [clang] Make source locations space usage diagnostics numbers easier to read (PR #114999)

[Ilya Biryukov via cfe-commits]

ilya-biryukov wrote:

Do we really care about the exact byte numbers? Maybe we should only show the human-friendly version?
It's appealing to have less noise if we can.

https://github.com/llvm/llvm-project/pull/114999