i965: Track non-compressible sampling of renderbuffers

v3:
   - Actually set the flags when needed instead of falsely
     overwriting them (Jason).
   - Use more generic name for flag (dropped RENDERBUFFER)
   - Consult also shader images
v4:
   - Consult only lossless compressd shader images

v5:
   - Check the existence of renderbuffer before considering
     if it matches the given miptree

Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
3 files changed