Describe the Bug

When working on a cross-build for Linux, @directhex noted that the blob feed and artifacts directories still specify x64: #3671 (comment). We should rework these directory names.

Steps to Reproduce

See #3671 (comment) for info.

Other Information

My guess is that the target arch should be in the name of the directory, rather than the host. Furthermore, it may make sense to change 'blob-feed' to something meaningful (intermediate-assets?). 'blob-feed' refers to a bit of ancient technology we used to use for NuGet feeds in the 2.1 timeframe (Sleet).

T-Shirt size: XS