stdlib: Allow JSON resources file to be set via env-var

Via the "GEM5_RESOURCE_JSON" environment variable, a user can override
the the default resources.json retrieval location. E.g., a user can have
their own resources.json file and load it instead. This may be a local
file path or a URL.

Code has been changed in downloader.py to allow the loading of
resources.json from either a URL or a local file path. Previously only
URLs were valid.

Change-Id: I022eee58efadc4819069563e9046ce9d84e5cf06
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/59069
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed