Remove VarType from trace_var opcode.

This is redundant information now that we have SkVMSlotInfo.

Change-Id: Ia05b1eaa722023e719042c83255708aa9debed61
Bug: skia:12614
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/473777
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
8 files changed