main: Refactor _mesa_texture_buffer_range.

Changes how the caller is identified in error messages, moves a check for
ARB_texture_buffer_object from the entry points to the shared code in
_mesa_texture_buffer_range, and removes an unused argument (GLenum target).

v2: Review from Anuj Phogat
   - Split rebase of Tex[ture]Buffer[Range]

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
2 files changed