Only do trick when enabled, check neg as well as pos NA/NaN
Merge branch '03-ISNAN' into 04
Merge branch '03-ISNAN' into 04-coerce-bind
Merge branch '03-ISNAN' into 04-dollar
Merge branch '03-ISNAN' into 04-ifloop-debug
Merge branch '03-ISNAN' into 04-relop-logic
Merge branch '03-ISNAN' into 04-subscript
Merge branch '03-ISNAN' into 04-vec-enlarge
Merge branch '03-ISNAN' into 04-vec-subset
Merge branch '03-ISNAN' into 05
Merge branch '03-ISNAN' into 05-pow
move type sets to Rinternals.h, update mods entry
Merge branch '03-inlined' into 04
Merge branch '03-inlined' into 04-coerce-bind
Merge branch '03-inlined' into 04-dollar
Merge branch '03-inlined' into 04-ifloop-debug
Merge branch '03-inlined' into 04-relop-logic
Merge branch '03-inlined' into 04-subscript
Merge branch '03-inlined' into 04-vec-enlarge
Merge branch '03-inlined' into 04-vec-subset