When precompiling SkSL, avoid the need to re-link

Adds metadata to the SkSL blobs about attributes (and other resources)
so that we can do all necessary work during precompile.

Change-Id: I1846c6c96946d5a43a48112d062853717a6571a0
Bug: skia:9402
Bug: b/140174804
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/243739
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
6 files changed