How to get function argument points-to information.

[Matt Davis]

For some analysis I am doing, I need to determine if a particular SSA_NAME_VAR
node is pointed-to by a function argument.  I am iterating across the function's
arguments via DECL_ARGUMENTS(), but each argument is just a DECL node, and
contains no associated points-to data, as far as I can tell.  I assume there is
a better/different way of determining if an argument points to my node?

Thanks for any insight.

-Matt