This is the last part for handling the minidump slow downs: - it removes the integration of RUNTIME_INFO chunks for x86_64 - adds fallback mechanism to read this unwind info from winedbg side. Some remarks: - it looks a bit awkward that SymFunctionTableAccess reads PE information from PE image on dbghelp side, while the unwind information reading is read (in this MR) from debugger side - some testings with native show that: + unwind info (inside StackWalk calls) is read through the read memory handler (so delegated to debugger) + there's no fallback from the read memory handler - so this looks like the minimal things to do - however, there could be additional fallback in dbghelp (like in dbghelp internal read memory handler); didn't spend time on these as they would only be helpful for non live targets, using the default read memory handler. - fixed winedbg to reload properly minidumps.