[ET Trac] [Einstein Toolkit] #680: Add kifneg function

#680: Add kifneg function -----------------------------------+---------------------------------------- Reporter: eschnett | Owner: Type: enhancement | Status: new Priority: minor | Milestone: Component: EinsteinToolkit thorn | Version: Keywords: | -----------------------------------+---------------------------------------- Add an kifneg function that does the opposite of kifpos, because kifneg is more natural (in the same sense as "ifnotzero" is natural in C.)

Incidentally, it should probably be renamed "ifmsb" instead, because it can also be applied to unsigned quantities which don't have a sign bit.