Replace SkSL rehydrator with minified code.

The Rehydrator takes 17-19K worth of binary size, and the dehydrated
IR is larger than the equivalent SkSL, once comments and whitespace
are stripped out.

Change-Id: Ifd29e2537c23591af7e73969535847e8f48ccf70
Bug: skia:13764
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/584920
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
8 files changed