I changed callfv's way of calling a function with arguments in vm_vec.
now callfv fetches arguments from val_stack directly,so it runs test/fib.nas from 2.4s to 1.9s.
delete operand callf,add operands callfv & callfh.
also,i check val_stack's top to make sure there is not a stack overflow.
a gc bug which causes fatal error.
add member value collect to make sure that nasal_val is not collected repeatedly.
use builtin_alloc in builtin function to avoid incorrect collection of value in use(gc_alloc).
change free_list to free_list[vm_type_size] to avoid too many calls of new/delete(but seems useless?)
but the most important thing is fixing this bug.
add operand op_offset to make sure arguments are loaded at correct places,before this commit,arguments are not loaded from a correct offset,which will cause SIGSEGV when calling a function that has complex closure
fixed a bug when different hash calling the same function,'me' will be set to the latest called hash's address.
changed the way of pushing the scope to the stack by copying a new scope from the function's scope address.
use map as the nasal_scop instead of list<map>,it'll be more efficient.
Valk Richard Li