Make IRGenerator::call propagate poison

This fixes redundant "not a function" errors when we have already
produced an error resolving the target of a call.

Change-Id: I94876ec09feac399108033d1b850e78c7750dd1d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/443411
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
1 file changed