Clean up ARM subtarget code by using Triple ADT.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123276 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMSubtarget.cpp b/lib/Target/ARM/ARMSubtarget.cpp
index 2b53cfd..5dfd5d7 100644
--- a/lib/Target/ARM/ARMSubtarget.cpp
+++ b/lib/Target/ARM/ARMSubtarget.cpp
@@ -13,6 +13,7 @@
 
 #include "ARMSubtarget.h"
 #include "ARMGenSubtarget.inc"
+#include "ARMBaseRegisterInfo.h"
 #include "llvm/GlobalValue.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Support/CommandLine.h"
@@ -56,7 +57,7 @@
   , AllowsUnalignedMem(false)
   , stackAlignment(4)
   , CPUString("generic")
-  , TargetType(isELF) // Default to ELF unless otherwise specified.
+  , TargetTriple(TT)
   , TargetABI(ARM_ABI_APCS) {
   // Default to soft float ABI
   if (FloatABIType == FloatABI::Default)
@@ -118,12 +119,6 @@
     }
   }
 
-  if (Len >= 10) {
-    if (TT.find("-darwin") != std::string::npos)
-      // arm-darwin
-      TargetType = isDarwin;
-  }
-
   if (TT.find("eabi") != std::string::npos)
     TargetABI = ARM_ABI_AAPCS;