Feature like add-symbol-file for Valgrind

I'm debugging a mingw-compiled exe running under Wine, and I'm getting 
some invalid reads in chkstk.  Assuming I don't want to "skip past" them 
but detect and suppress them, the most natural thing to do would be to 
create and use a suppressions file.

However, the code that calls into chkstk is loaded outside of the normal 
"dlopen" code path, and neither Valgrind nor GDB loads symbols for it 
before it is jumped into.  With GDB I can use "add-symbol-file" to state 
where to find the symbols for it.  Does Valgrind have a similar option?

Thanks,
Jefferson