fixed skslc's handling of ivec(vec)

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4222

Change-Id: I9b32067af51f3a04efa702cf2eb1ac1ed480df6a
Reviewed-on: https://skia-review.googlesource.com/4222
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
3 files changed