[ELF][MIPS] Turn Config->Threads off for MIPS targets

[atanasyan]

Summary

For now MipsGotSection class is not ready for concurrent access from multiple threads. The problem is in the getPageEntryOffset method. It changes state of MipsGotSection object and might be called from different threads at the same time. So turn Threads off for this target.

It's a temporary solution. The patch fixes MipsGotSection::getPageEntryOffset is almost ready.

[ruiu]

LGTM

lld/trunk/ELF/Driver.cpp

void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->SaveTemps = Args.hasArg(OPT_save_temps);
   Config->Shared = Args.hasArg(OPT_shared);
   Config->Target1Rel = getArg(Args, OPT_target1_rel, OPT_target1_abs, false);
   Config->Threads = getArg(Args, OPT_threads, OPT_no_threads, true);
   Config->Trace = Args.hasArg(OPT_trace);
   Config->Verbose = Args.hasArg(OPT_verbose);
   Config->WarnCommon = Args.hasArg(OPT_warn_common);
 
+  if (Config->EMachine == EM_MIPS)
+    // For now MipsGotSection class is not ready for concurent access
+    // from multiple thread. The problem is in the getPageEntryOffset
+    // method. So turn Threads off for this target.
+    Config->Threads = false;
+
   Config->DynamicLinker = getString(Args, OPT_dynamic_linker);
   Config->Entry = getString(Args, OPT_entry);
   Config->Fini = getString(Args, OPT_fini, "_fini");
   Config->Init = getString(Args, OPT_init, "_init");
   Config->LtoAAPipeline = getString(Args, OPT_lto_aa_pipeline);
   Config->LtoNewPmPasses = getString(Args, OPT_lto_newpm_passes);
   Config->OutputFile = getString(Args, OPT_o);
   Config->SoName = getString(Args, OPT_soname);