-Zhuman-readable-cgu-names generates filenames that exceed the character limit on windows

[Diggsey]

I ran into this error while trying to determine which crates were contributing to bloated rlib sizes:

error: could not write output to D:\Projects\platformed\rust\target\debug\deps\platformed.http.f916976a8c6a0cf4-in-platformed.f916976a8c6a0cf4-response.volatile--tracing_subscriber.f916976a8c6a0cf4-in-platformed.f916976a8c6a0cf4-registry-sharded--tracing_subscriber.f916976a8c6a0cf4-in-platformed.f916976a8c6a0cf4-registry-stack.0bt72is.rcgu.o: invalid argument

The filename is conspicuously just over 255/260 characters long which are limits on windows for filenames.