Makefile updates to productionize the release

Change-Id: I9b043641f2c978d50cc4ae6492dff74ad5f006d6
Reviewed-on: https://swiftshader-review.googlesource.com/3019
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Greg Hartman <ghartman@google.com>
6 files changed