mesa: Enable GL_NV_pack_subimage
This just legalizes a few of the pixelstore pack parameters in GLES2 that are already legal in desktop and GLES3. glamor takes advantage of this in the GetImage and software-fallback paths.
This just legalizes a few of the pixelstore pack parameters in GLES2 that are already legal in desktop and GLES3. glamor takes advantage of this in the GetImage and software-fallback paths.