Revert "Trimmed the branch to only the 3rdparty/downward sub directory"

This reverts commit b991fcd2eda0d9eb8cb9afd8e6f3385a54afc1d3.
Rebase from 'upstream'
Trimmed the branch to only the 3rdparty/downward sub directory
Revert "Trimmed the branch to only the 3rdparty/downward sub directory"

This reverts commit 2e1e842ffc4979a6c16a35df16c012881b468381.
Rebase from 'upstream' (no changes)
Trimmed the branch to only the 3rdparty/downward sub directory