Fix various SkSL errors that don't report a line number.

Change-Id: I1a96060b2e52cddb50948a48520aab30bd097bbd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/343577
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
11 files changed