m32c.c (m32c_function_arg): Structures are always passed on the stack.

m32c.c (m32c_function_arg): Structures are always passed on the stack.

* config/m32c/m32c.c (m32c_function_arg): Structures are always
passed on the stack.
(m32c_init_cumulative_args): When a function returns a structure,
always pass the pointer to that return area on the stack.
(m32c_function_arg_advance): Don't increment the parameter number
if we're processing the returned structure pointer.
(pushm_info): Reverse order of registers.

From-SVN: r112765