A bare module-global unsigned operand got signed IDIV/SAR/Jcc — the
predicate's ident arm only consulted the local table, so globals fell
through to signed (review finding #25). Read the stamp for the global
arm; corpus emission is unmoved (no bootstrap code div/shift/cmps a
bare unsigned global). 989_gunsigned_run pins cs==ww (red 3/8
pre-fix).
