print XYZ matrix in custom way

This ramps up the number of digits printed until
we find a float that roundtrips correctly.

Locally build/emscripten is now okay (and had always
been producing the correct float, just printing funny.)

Change-Id: I789ccb19ab72e067fdc50a52b8a705f079c4b94f
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/199809
Auto-Submit: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
39 files changed