Add a note on recursive functions potentially breaking the unwinder

This happens for cpp-recursion e.g., see also issue #93

Author: milianw

README.md

@@ -221,6 +221,7 @@ notably, unwinding will fail when:
         perf record --call-graph dwarf,32768
 
     Note that this can dramatically increase the size of the `perf.data` files - use it with care. Also have a look at `man perf record`.
+  - For some scenarios, recursive function calls simply fail to be unwound. See also https://github.com/KDAB/hotspot/issues/93
 
 ### Missing Features