tests: skip SwiftShader tests when building without SwiftShader If we are building without SwiftShader, we shouldn't be forced to add a gtest_filter of "-*SwiftShader*" in order to run the various tests. Bug: angleproject:8291 Change-Id: Ic3513445d5d4bb402535a6f41bba818c0d15fd7a Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4769826 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Auto-Submit: Steven Noonan <steven@uplinklabs.net>