I test four size of 'tt_' with each struct assign method, the result is amazing.
#define setobj_X(L,obj1,obj2) \
{ TValue *io1=(obj1); *io1 = *(obj2); \
(void)L; checkliveness(L,io1); }
#define setobj_Y(L,obj1,obj2) \
{ TValue *io1=(obj1); const TValue *io2=(obj2); \
io1->value_ = io2->value_; io1->tt_ = io2->tt_; \
(void)L; checkliveness(L,io1); }
typeof(tt_) char short int long
setobj_X 0.55s 0.55s 0.55s 0.41s
setobj_Y 0.52s 0.43s 0.42s 0.42s
