move skvm debug tools back to core

I happened to have this on when profiling skottie_tool and got curious
why I was seeing the interpreter run and not JIT code.  Mostly this
moves the code in bulk out of SkVMTest.cpp to SkVM.cpp so that code in
SkVM.cpp can call dump() on itself.

Also this CL has the skvm::Program hang onto the original value-based
builder program (in addition to its own interpreter program and JIT
program if we can).  This is entirely so that when JIT bails out I
can have it dump out both the builder and interpreter programs for
more debugging aid.

I'm still going to need more debug tools somewhere to figure out
what the program that needs 17 registers is, and what to do about
it.

Finally, remove skvmtool.  It's annoying to maintain its build
rules, and I don't use it much if ever anymore.

Change-Id: I995d15d04bda79ddfc4d68bda8aaa3b5b9261f08
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/242520
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
5 files changed