Can not support external variables and can not support optimizations

[onlytheworld]

``Can not support external variables like
empty addr node load inst @xx_hold = external dso_local global %union.rec*, align 8 in func Next
can not support optimizations like O2,

empty di local var: Next1 - 1
empty di local var: Next1 - 1
empty di local var: Next1 - 1
empty addr node load inst i64* bitcast (%union.rec** @zz_res to i64*) in func Next
empty addr node load inst %struct.word_type*** bitcast (%union.rec** @zz_hold to %struct.word_type***) in func Next

for functions like

OBJECT Next(OBJECT x, int inc, BOOLEAN *done)
{ OBJECT y, link;  int l, r, n, len;
  FULL_CHAR buff[MAX_BUFF];
  debug3(DCS, DD, "Next( %s, %d, %s )", EchoObject(x), inc, bool(*done));
  switch( type(x) )