Switch build to use Clang. This somewhat degrades FFI testing, but reduces build time by roughly half or one hour.
Cq-Include-Trybots: luci.dart.try:pkg-win-release-arm64-try,vm-aot-win-debug-arm64-try,vm-aot-win-release-arm64-try,vm-win-debug-arm64-try,vm-win-release-arm64-try
Change-Id: Ie267942e99934312b228cfadcd6d5b8477f855c8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/429421
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Ryan Macnak
f4fa8b7ca6