Interpreter: Fix scalar -> vector constructors

We were never replicating scalar values when constructing vector types
from a single argument.

Change-Id: I5bdeeb91f5a10c151b18561de6c275f2db2898fe
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215526
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: Brian Osman <brianosman@google.com>
2 files changed