Fixed SkSL visitor to match previous node counts
Fixed SkSL visitor to match previous node counts

The SkSL analyzer did not visit VarDeclarations program elements,
whereas the previous nodeCount() system did, leading to an unintentional
difference in effective inlining thresholds. The more relaxed inlining
threshold was leading to compiler hangs on Metal.

Change-Id: Ic4980f3238cb644e395525edca6737c996225b2e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/312836
Commit-Queue: Ethan Nicholas <d2cfb8c2f603266f4dc3a6f09acbcc0089603b37@google.com>
Commit-Queue: Jim Van Verth <509afb0bfbb23ecaaf1fb3323209f531b45e75a6@google.com>
Auto-Submit: Ethan Nicholas <d2cfb8c2f603266f4dc3a6f09acbcc0089603b37@google.com>
Reviewed-by: Jim Van Verth <509afb0bfbb23ecaaf1fb3323209f531b45e75a6@google.com>

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