Add -femulated-tls flag to select the emulated TLS model.

This will be used for old targets like Android that do not
support ELF TLS models.

Differential Revision: http://reviews.llvm.org/D10524

llvm-svn: 243441

clang/lib/Frontend/CompilerInvocation.cpp

@@ -593,6 +593,9 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
     }
   }
 
+  Opts.EmulatedTLS =
+      Args.hasFlag(OPT_femulated_tls, OPT_fno_emulated_tls, false);
+
   if (Arg *A = Args.getLastArg(OPT_ftlsmodel_EQ)) {
     StringRef Name = A->getValue();
     unsigned Model = llvm::StringSwitch<unsigned>(Name)