iris: Support clears in more GPU-based copies
Commit 7779b1d7, disabled clear support when copying to/from color buffers. According to the performance CI, it falls within a range of commits that introduced a performance regression on Bioshock Infinite with Tigerlake.
By analyzing a trace of the game, I found a couple cases where that commit added new partial resolves. This MR avoids them. I haven't tested the actual performance impact of this change, but it should be beneficial regardless.
Reported-by: @craftyguy , @jljusten