FIXED: set_breakpoint/4: avoid exception if layout information is only partially available.
FIXED: set_breakpoint/4: avoid exception if layout information is only
partially available.

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