If we have a source file with a non Latin1 character in the file name (e.g. λ.file)

• and it is referenced in a glob(), let's say to attribute srcs (of type label_list)
• and you evaluate attr.srcs[n].label.name
• the length of the string is 7 on linux and macos
• but it is 6 on windows

Hilarity ensues while trying to figure out how to write these strings as part of an action.
Discovered while trying to fix #10174 More details to follow.