DSLParser now tracks parse errors separately from semantic errors

With SkSLParser, all errors were fatal. But with DSLParser, semantic
errors can occur in the middle of parsing, and we need to be able to
distinguish the two so we know whether or not to stop parsing.

Change-Id: I125901d8ee9ac28480ff7f1ddb825b1e14468a6f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/443409
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
2 files changed