[Apple Silicon] Support attach by name correctly for Rosetta.

[davide]

Summary

The fix is that of updating attach_info with pid once we discover it, if we specified to attach by name (otherwise, the process is treated as native).

[davide]

This landed in a different form.

lldb/source/Target/Process.cpp

           const uint32_t num_matches = process_infos.size();
           if (num_matches == 1) {
             attach_pid = process_infos[0].GetProcessID();
+            // attach_info will be passed to DoAttachToProcessWithID()
+            // which uses the pid to determine if this is a translated
+            // process so include the pid we just found in the attach_info.
+            attach_info.SetProcessID(attach_pid);
+
             // Fall through and attach using the above process ID
           } else {
             match_info.GetProcessInfo().GetExecutableFile().GetPath(