Support initializers on global variables in SkSL to SkVM

Bug: skia:11295
Change-Id: I72c09b75a3ff5d668e99dcc3620850b82071b560
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371340
Reviewed-by: Mike Klein <mtklein@google.com>
2 files changed