* Fixed DXC installation so that we download the latest release, and
patch it with the latest artifact build. This ensures that the correct
dxil.dll is next to dxc.exe, rather than having dxc.exe pick up whatever
dxil.dll is in PATH.
* To run tests with FXC requires the correct d3dcompiler_47.dll. To do
this, I modified the script to download the Windows SDK, and install
only the feature that contains the DLL.
* To avoid issues with DXC and FXC finding exes/dlls in PATH, modified
the script to temporarily set PATH as needed.
Bug: tint:940
Change-Id: Ic83b0b97f72ccc1f37b4b495eae6a6ab3421a95a
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/72560
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>