Fix DSL handling of doubles

Previously, "x = 1.0" (as opposed to 1.0f) would fail with an ambiguous
operator resolution.

Change-Id: I9bcb4115d209a2aadb3fc4c237b61c345b25ca00
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/400619
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
4 files changed