Use -mc-relax-all flag for sandboxed translator

tools/pnacl-llc/pnacl-llc.cpp

 //===-- pnacl-llc.cpp - PNaCl-specific llc: pexe ---> nexe  ---------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // pnacl-llc: the core of the PNaCl translator, compiling a pexe into a nexe.
@@ skipping 687 matching lines @@
   std::string Error;
   const Target *TheTarget = TargetRegistry::lookupTarget(MArch, TheTriple,
                                                          Error);
   if (!TheTarget) {
     errs() << ProgramName << ": " << Error;
     return 1;
   }
 
   TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
   Options.DisableIntegratedAS = NoIntegratedAssembler;
+#if defined(__native_client__)
+  Options.MCOptions.MCRelaxAll = true;

[Mark Seaborn, 2015/05/15 14:03:42]

Can you add a comment explaining that this reduces memory use (citing the issue
perhaps) and why we enable it only for the sandboxed build of pnacl-llc?

[Petr Hosek, 2015/05/15 19:27:39]

Done.

+#endif
 
   if (GenerateSoftFloatCalls)
     FloatABIForCalls = FloatABI::Soft;
 
   // Package up features to be passed to target/subtarget
   std::string FeaturesStr;
   if (MAttrs.size()) {
     SubtargetFeatures Features;
     for (unsigned i = 0; i != MAttrs.size(); ++i)
       Features.AddFeature(MAttrs[i]);
@@ skipping 51 matching lines @@
   return 0;
 }
 
 int main(int argc, char **argv) {
 #if defined(PNACL_BROWSER_TRANSLATOR)
   return srpc_main(argc, argv);
 #else
   return llc_main(argc, argv);
 #endif // PNACL_BROWSER_TRANSLATOR
 }