LG_STACK_HEURISTIC 1864 src/sysdep.c       return 0 <= addr - top && addr - top < (top - bot) >> LG_STACK_HEURISTIC;
LG_STACK_HEURISTIC 1866 src/sysdep.c       return 0 <= top - addr && top - addr < (bot - top) >> LG_STACK_HEURISTIC;