Replace string GNU Triples with llvm::Triple in MCSubtargetInfo and create*MCSubtargetInfo(). NFC.

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

Reviewers: rafael

Reviewed By: rafael

Subscribers: rafael, ted, jfb, llvm-commits, rengolin, jholewinski

Differential Revision: http://reviews.llvm.org/D10311

llvm-svn: 239467
diff --git a/llvm/lib/Target/X86/X86Subtarget.cpp b/llvm/lib/Target/X86/X86Subtarget.cpp
index 74af29f..1657d7d 100644
--- a/llvm/lib/Target/X86/X86Subtarget.cpp
+++ b/llvm/lib/Target/X86/X86Subtarget.cpp
@@ -287,7 +287,7 @@
   return *this;
 }
 
-X86Subtarget::X86Subtarget(const std::string &TT, const std::string &CPU,
+X86Subtarget::X86Subtarget(const Triple &TT, const std::string &CPU,
                            const std::string &FS, const X86TargetMachine &TM,
                            unsigned StackAlignOverride)
     : X86GenSubtargetInfo(TT, CPU, FS), X86ProcFamily(Others),