[graphite] Add compile guards to precompile system (take 2)

Bug: skia:13430
Change-Id: I64d6049fec8cc942a8f7c56c01ba292cc8f3835c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/554378
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
26 files changed