Added parameters to support:
- Mapping a subset of a buffer
- New texture features like swizzling, min/max LOD,
  texture comparison modes, etc.

Change-Id: Iffd961a3aeab33cb95892f93d78d3888ce60e401
Reviewed-on: https://swiftshader-review.googlesource.com/2780Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>