Remove vector of ModifierPools for core modules.

There's no benefit to isolating each module's modifier pool from each
other. It's simpler and more efficient to lump all the modules'
modifiers into one shared pool which (like the modules themselves)
exists as long as the Compiler does.

Change-Id: I8335a410e788d2c5142b820407beddf5c2663eef
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/404336
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2 files changed