freedreno/ir3: insert mov if same instruction in the outputs.

freedreno/ir3: insert mov if same instruction in the outputs.

For example,

    result0 = texture(sampler[indexBase + 5], coords);
    result1 = texture(sampler[indexBase + 0], coords);
    result2 = texture(sampler[indexBase + 0], coords);
    out_result0 = result0;
    out_result1 = result1;
    out_result2 = result2;

In this kind of case we need to insert an extra mov to the outputs
so that the result could be assigned to each register respectively.

Signed-off-by: Rob Clark <robdclark@gmail.com>