i965: Momentarily pretend to support ARB_texture_stencil8 for blits.
Broadwell's stencil blitting code attempts to bind a renderbuffer as a texture, using dd->BindRenderbufferTexImage(). This calls _mesa_init_teximage_fields(), which then attempts to set img->_BaseFormat = _mesa_base_tex_format(ctx, internalFormat), which assert fails if internalFormat is GL_STENCIL_INDEX8 but ARB_texture_stencil8 is unsupported. To work around this, just pretend to support the extension momentarily, during the blit. Meta has already munged a variety of other things in the context (including the API!), so it's not that much worse than what we're already doing. Fixes regressions since commit f7aad9da (mesa/teximage: use correct extension for accept stencil texture.). v2: Add an XXX comment explaining the situation (requested by Jason Ekstrand and Martin Peres), and an assert that we don't support the extension so we remember to remove this hack (requested by Neil Roberts). Signed-off-by:Kenneth Graunke <kenneth@whitecape.org> Reviewed-by:
Jason Ekstrand <jason.ekstrand@intel.com> (cherry picked from commit f83b9e58) Nominated-by:
Mark Janes <mark.a.janes@intel.com>