Refactored IRGenerator::convertInterfaceBlock

Previously the magic surrounding sk_RTAdjust was inaccessible to the
DSL, meaning that the DSLParser would not work properly when the
sk_RTAdjust field was present in an interface block. This refactoring
means all interface blocks are processed via the same path.

Change-Id: I99a2fe6875dfcbccc53f7a44f0fb1912cb2722ce
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/442456
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
4 files changed