Kokoro: fix Tint e2e tests not using DXC, and using the wrong FXC

This was broken in https://dawn-review.googlesource.com/c/dawn/+/116299

Change-Id: I8a0a89bfb842a4bb3a9efb32141a4624315f29b6
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/162362
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
diff --git a/infra/kokoro/windows/build.bat b/infra/kokoro/windows/build.bat
index 3d93c08..2935447 100644
--- a/infra/kokoro/windows/build.bat
+++ b/infra/kokoro/windows/build.bat
@@ -168,7 +168,7 @@
 cd /d %SRC_DIR% || goto :error
 rem Run tests with DXC, FXC and Metal validation
 set OLD_PATH=%PATH%
-set PATH=C:\Program Files\Metal Developer Tools\macos\bin;%PATH%
+set PATH=C:\Program Files\Metal Developer Tools\macos\bin;%DXC_PATH%;%D3DCOMPILER_PATH%;%PATH%
 if "%BUILD_TYPE%" == "Debug" (
     rem TODO(crbug.com/2034): Add back glsl once we fix the ~7x slowdown in Windows Debug builds
     set TEST_ALL_FORMATS=wgsl,spvasm,msl,hlsl