Using the x86 binary is required for testing on Windows on Arm systems,
which can only emulate the x86 architecture at this time.

Change-Id: I28f01e3974b69ced4a96d8675adc024555791131
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2108724Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Richard Townsend <richard.townsend@arm.com>