Make `debug_sync` regex more robust

Make `debug_sync` regex more robust

On windows the symbol names appear to sometimes be truncated,
which causes the symbol name to not include the `::new` at the end.
This causes the regex to mis-match and track the wrong location
for the mutex construction, leading to bogus lockorder violations.

For example, in testing the following symbol name appeared on
Windows, without the function name itself:

`lightning::debug_sync::RwLock<std::collections::hash::map::HashMap<lightning::chain::transaction::OutPoint,lightning::chain::chainmonitor::MonitorHolder<lightning::util::enforcing_trait_impls::EnforcingSigner>,std::collections::hash::map::RandomState> >::`