[llvm-dev] [Path] RFC: Known directories

[Rafael Espíndola via llvm-dev]

> We appear to use both system_temp_directory(true) and
> system_temp_directory(false) in ways that seem like they could matter.
> For instance, modules uses a temp directory that does not get erased
> on reboot, possibly for performance reasons. Do we gain something from
> deprecating system_temp_directory()?

I have a small preference for having the distinction in the name:

*_temp_* -> something that is one use and potentially deleted often
*_cache_* -> something we would like to save (modules for example).

So what we gain is clarity over a bool parameter.

Cheers,
Rafael