Improve distinct-out-param test cases.

Added new aliasing tests inspired by syoussefi@'s ANGLE changes at
http://go/crrv/c/3561278.

Change-Id: Ifa312faa9503b211b7c09edd2abd5087ead35e5f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/526018
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Arman Uguray <armansito@google.com>
Commit-Queue: Arman Uguray <armansito@google.com>
10 files changed