ENHANCED: ansi_format/3: flush output to avoid mixing with error messages and typecheck the SGR code.
ENHANCED: ansi_format/3: flush output to avoid mixing with error messages
and typecheck the SGR code.

edechter/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,koryonik/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,edechter/swipl-devel,mndrix/swipl-devel,mndrix/swipl-devel