Replace string GNU Triples with llvm::Triple in TargetMachine. NFC.

Summary:
For the moment, TargetMachine::getTargetTriple() still returns a StringRef.

This continues the patch series to eliminate StringRef forms of GNU triples
from the internals of LLVM that began in r239036.

Reviewers: rengolin

Reviewed By: rengolin

Subscribers: ted, llvm-commits, rengolin, jholewinski

Differential Revision: http://reviews.llvm.org/D10362

llvm-svn: 239554
diff --git a/llvm/lib/Target/BPF/BPFTargetMachine.h b/llvm/lib/Target/BPF/BPFTargetMachine.h
index 6aeafb9..a0086df 100644
--- a/llvm/lib/Target/BPF/BPFTargetMachine.h
+++ b/llvm/lib/Target/BPF/BPFTargetMachine.h
@@ -23,8 +23,8 @@
   BPFSubtarget Subtarget;
 
 public:
-  BPFTargetMachine(const Target &T, StringRef TT, StringRef CPU, StringRef FS,
-                   const TargetOptions &Options, Reloc::Model RM,
+  BPFTargetMachine(const Target &T, const Triple &TT, StringRef CPU,
+                   StringRef FS, const TargetOptions &Options, Reloc::Model RM,
                    CodeModel::Model CM, CodeGenOpt::Level OL);
 
   const BPFSubtarget *getSubtargetImpl() const { return &Subtarget; }