Clean up some usage of Triple.  The base class has methods for determining if the target is iOS and Linux.

llvm-svn: 189604
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index ad7f1b3..b13ff9d 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -275,10 +275,10 @@
 
   const Triple &getTargetTriple() const { return TargetTriple; }
 
-  bool isTargetIOS() const { return TargetTriple.getOS() == Triple::IOS; }
+  bool isTargetIOS() const { return TargetTriple.isiOS(); }
   bool isTargetDarwin() const { return TargetTriple.isOSDarwin(); }
-  bool isTargetNaCl() const { return TargetTriple.getOS() == Triple::NaCl; }
-  bool isTargetLinux() const { return TargetTriple.getOS() == Triple::Linux; }
+  bool isTargetNaCl() const { return TargetTriple.isOSNaCl(); }
+  bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
   bool isTargetELF() const { return !isTargetDarwin(); }
   // ARM EABI is the bare-metal EABI described in ARM ABI documents and
   // can be accessed via -target arm-none-eabi. This is NOT GNUEABI.