Added clear color image command
Added clear color image command

Added the command to send the clear color image command
to the Image object.

Bug b/118619338

Change-Id: Ic4e00fbd49e8e043df1d2e707e3c26dadf159790
Reviewed-on: https://swiftshader-review.googlesource.com/c/23653
Tested-by: Alexis Hétu <1c7141772178a7e80858c3db5052b328076f08f4@google.com>
Reviewed-by: Chris Forbes <c3279c50043e18e9442c1ae071cafa0e7a4ca967@google.com>
Reviewed-by: Corentin Wallez <470c533e86f4f848c98c7e11fffc2d043494a401@google.com>

google/swiftshader,bkaradzic/SwiftShader,google/swiftshader,google/swiftshader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,bkaradzic/SwiftShader