Function dt_decl_func

* When a function is declared, we need to fudge the decl stack a bit if the * declaration uses the function pointer (*)() syntax. In this case, the * dt_decl_func() call occurs *after* the dt_decl_ptr() call, even though the * resulting type is "pointer to function". To make the pointer land on top, * we check to see if 'pdp' is non-NULL and a pointer. If it is, we search * backward for a