remove aarch64 offline compilation

The baseline compiled into Skia is now pretty much identical.

Minor diffs due to the offline code using -ffp-contract=fast, and the
baseline not.  Explicit calls to fma() are still FMAs, but we're no
longer letting the compiler uncover FMAs we didn't explicitly call out.

If this goes well, we should be able to turn on the 8-bit pipeline.

Change-Id: I8f73157cfce7373574c20f6435fe86b46477afa9
Reviewed-on: https://skia-review.googlesource.com/39520
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
3 files changed