scons: default to not duplicating sources in the build directory

We now default to --no-duplicate-sources, but keep --duplicate-sources to
opt-out of this new build behaviour in case it introduces regressions.

Change-Id: I2f01ceaef7b6b9bff80f4402081f007110f7e6f3
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/68758
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed