bits integer (including character)
is sign-extended and passed to a C function via stack.
30-bit float is extended to double and passed via stack.
As for string, integer-vector and float-vector,
only the address of the first element is passed on the stack,
and the entire array remains uncopied.
The string can either be a normal string or a foreign-string.
A string may contain null codes, though it is guaranteed
that the string also has a null code at the end.
EusLisp does not know how to pass arrays of more