Revert "Disable F16-nullptr sources"

Manual revert: failing ui rendering cts tests

Bug: b/62482405
Change-Id: I652ec8dce482d303437835a27c50a22248afd955
Reviewed-on: https://skia-review.googlesource.com/19360
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>
4 files changed