A few SOS commands fail on a Linux single-file app under lldb at process launch

When lldb stops on a `process launch -s` for a single-file app, the ELF symbol data structures are not initialized yet (RVA's instread of address), so SOS can't find the runtime info structure causing any command that needs to find the runtime (setclrpath, runtimes, etc.) fails. We may be able to detect this in the clrmd ELF reader used to find the runtime info symbol (RVA's vs. addresses).

Reenable the `setclrpath` command in the SOSRunner.cs (around line 927) after this is fixed.