fix forward/backward jump logic
fix forward/backward jump logic

By the time we do this check, we've consumed all the bytes for the
branchIfAllFalse instruction, so ip is pointing at the next instruction.

If that next instruction is itself the jump target, we classify that as
a backward jump instead of the zero-sized forward jump that it is.

Switching to >= fixes that.

Change-Id: I537131bfb0d213c8407734184b78a510624d60c5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/327458
Auto-Submit: Mike Klein <14574f09dfa9b4e14759b88c3426a495a0e627b0@google.com>
Commit-Queue: Brian Osman <794c0b5534edf5601d88e1d41975d0262da12894@google.com>
Reviewed-by: Brian Osman <794c0b5534edf5601d88e1d41975d0262da12894@google.com>

google/skia,google/skia,google/skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia