flip_test: add logic to track pending events
flip_test: add logic to track pending events

When we add the vblank tests later, it can happen that one type of event
is pending while we are servicing another. Prepare for that by
maintaining a pending/completed event mask.

No functional change.

Signed-off-by: Imre Deak <fbd5edba1988036c8923f0cca0cce6ac4811db29@intel.com>

tiagovignatti/intel-gpu-tools,erikarn/intel-gpu-tools,yipdw/intel-gpu-tools,mv0/intel-gpu-tools,dlespiau/checkmate-test-igt,ChrisCummins/intel-gpu-tools,yipdw/intel-gpu-tools,dlespiau/checkmate-test-igt,chenxianqin/intel-gpu-tools,dlespiau/intel-gpu-tools,rib/intel-gpu-tools,erikarn/intel-gpu-tools,rib/intel-gpu-tools,chenxianqin/intel-gpu-tools,rib/intel-gpu-tools,ChrisCummins/intel-gpu-tools,dlespiau/intel-gpu-tools,yipdw/intel-gpu-tools,rib/intel-gpu-tools,tiagovignatti/intel-gpu-tools,chenxianqin/intel-gpu-tools,ChrisCummins/intel-gpu-tools,dlespiau/checkmate-test-igt,tiagovignatti/intel-gpu-tools,ChrisCummins/intel-gpu-tools,erikarn/intel-gpu-tools,yipdw/intel-gpu-tools,erikarn/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools,dlespiau/intel-gpu-tools,dlespiau/checkmate-test-igt,tiagovignatti/intel-gpu-tools