Add basic line table to VTune hooks

This maps all loop overhead instructions to "line 1",
each constant to its own line 2,3,4,... and each real
program instruction to 1000,1001,1002,...

It's vaguely helpful in VTune to see these notes.

Change-Id: If909e9dd5086ce02fbc217d206e4526356b268f7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255337
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
2 files changed