Update the libiberty demangler using the auxprogs/update-demangler
script to gcc git commit d3b2ead595467166c849950ecd3710501a5094d9.
This update includes:
- libiberty rust-demangle, ignore .suffix
- libiberty: Fix infinite recursion in rust demangler
- Update copyright years
- libiberty: support digits in cpp mangled clone names
- d-demangle: properly skip anonymous symbols
- d-demangle: remove parenthesis where it is not needed