Don't remove PIE executables when using svr4 packets

[fjricci]

Summary

Because PIE executables have an e_type of llvm::ELF::ET_DYN,
they are not of type eTypeExecutable, and were being removed
when svr4 packets were used.

[fjricci]

Fix curly-brace style

[fjricci]

Refactor to remove unnecessary object file type checking

[tfiala]

LGTM.

[sas]

Nit: Adding a comment explaining why we special-case the main executable (i.e.: because it is never included in libraries-svr4 packets) might be useful here.

source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp

if (new_modules.GetSize() > 0)
             {
                 if (new_modules.GetModuleAtIndex(j).get() == loaded_module.get())
                     found = true;
             }
 
             if (!found)
             {
                 lldb_private::ObjectFile * obj = loaded_module->GetObjectFile ();
-                if (obj && obj->GetType () != ObjectFile::Type::eTypeExecutable)
+                if (obj && obj->GetType () != ObjectFile::Type::eTypeExecutable &&
+                    loaded_module.get() != target.GetExecutableModulePointer()) {
                     removed_modules.Append (loaded_module);
                 }
             }
+        }
 
         loaded_modules.Remove (removed_modules);
         m_process->GetTarget().ModulesDidUnload (removed_modules, false);
 
         new_modules.ForEach ([&target](const lldb::ModuleSP module_sp) -> bool
         {
             lldb_private::ObjectFile * obj = module_sp->GetObjectFile ();
             if (!obj)