Darwin: Pass -iphoneos-version-min to ld when building for ARM.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@81019 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index 3d8632e..b0cc9cb 100644
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -53,6 +53,9 @@
   /// GCC version to use.
   unsigned GCCVersion[3];
 
+  /// Whether this is this an iPhone toolchain.
+  bool IsIPhone;
+
   /// The directory suffix for this tool chain.
   std::string ToolChainDir;
 
@@ -60,12 +63,16 @@
   /// initialized.
   mutable std::string MacosxVersionMin;
 
+  /// The default iphoneos-version-min of this tool chain.
+  std::string IPhoneOSVersionMin;
+
   const char *getMacosxVersionMin() const;
 
 public:
   Darwin(const HostInfo &Host, const llvm::Triple& Triple, 
-             const unsigned (&DarwinVersion)[3],
-             const unsigned (&GCCVersion)[3]);
+         const unsigned (&DarwinVersion)[3],
+         const unsigned (&GCCVersion)[3],
+         bool IsIPhone);
   ~Darwin();
 
   void getDarwinVersion(unsigned (&Res)[3]) const {
@@ -84,10 +91,16 @@
     return MacosxVersionMin.c_str();
   }
 
+  const char *getIPhoneOSVersionStr() const {
+    return IPhoneOSVersionMin.c_str();
+  }
+
   const std::string &getToolChainDir() const { 
     return ToolChainDir;
   }
 
+  bool isIPhone() const { return IsIPhone; }
+
   virtual DerivedArgList *TranslateArgs(InputArgList &Args) const;
 
   virtual Tool &SelectTool(const Compilation &C, const JobAction &JA) const;