Fix assertion when running tests without suffix on Windows On Windows, we may omit suffix ".exe" when running an executable. However, this will trigger an assertion failure in current code and this CL is to fix this issue. Bug: angleproject:4640 Change-Id: I7edfdc0b4a7c590c874817530b19a812018b9288 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2206425 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>