Xcode: Drop XCODE_DEPEND_HELPER for Xcode >= 5

Xcode 5.0 now computes dependencies from files linked through
OTHER_LDFLAGS, so we no longer need the XCODE_DEPEND_HELPER hack to
re-link dependents when targets change.

Source/cmGlobalXCodeGenerator.cxx

@@ -431,13 +431,16 @@ cmGlobalXCodeGenerator::AddExtraTargets(cmLocalGenerator* root,
 
   // Add XCODE depend helper
   std::string dir = mf->GetCurrentOutputDirectory();
-  cmCustomCommandLine makecommand;
-  makecommand.push_back("make");
-  makecommand.push_back("-C");
-  makecommand.push_back(dir.c_str());
-  makecommand.push_back("-f");
-  makecommand.push_back(this->CurrentXCodeHackMakefile.c_str());
-  makecommand.push_back(""); // placeholder, see below
+  cmCustomCommandLine makeHelper;
+  if(this->XcodeVersion < 50)
+    {
+    makeHelper.push_back("make");
+    makeHelper.push_back("-C");
+    makeHelper.push_back(dir.c_str());
+    makeHelper.push_back("-f");
+    makeHelper.push_back(this->CurrentXCodeHackMakefile.c_str());
+    makeHelper.push_back(""); // placeholder, see below
+    }
 
   // Add ZERO_CHECK
   bool regenerate = !mf->IsOn("CMAKE_SUPPRESS_REGENERATION");
@@ -477,17 +480,18 @@ cmGlobalXCodeGenerator::AddExtraTargets(cmLocalGenerator* root,
       // run the depend check makefile as a post build rule
       // this will make sure that when the next target is built
       // things are up-to-date
-      if((target.GetType() == cmTarget::EXECUTABLE ||
+      if(!makeHelper.empty() &&
+         (target.GetType() == cmTarget::EXECUTABLE ||
 // Nope - no post-build for OBJECT_LIRBRARY
 //          target.GetType() == cmTarget::OBJECT_LIBRARY ||
           target.GetType() == cmTarget::STATIC_LIBRARY ||
           target.GetType() == cmTarget::SHARED_LIBRARY ||
           target.GetType() == cmTarget::MODULE_LIBRARY))
         {
-        makecommand[makecommand.size()-1] =
+        makeHelper[makeHelper.size()-1] = // fill placeholder
           this->PostBuildMakeTarget(target.GetName(), "$(CONFIGURATION)");
         cmCustomCommandLines commandLines;
-        commandLines.push_back(makecommand);
+        commandLines.push_back(makeHelper);
         lg->GetMakefile()->AddCustomCommandToTarget(target.GetName(),
                                                     no_depends,
                                                     commandLines,
@@ -3338,8 +3342,11 @@ void cmGlobalXCodeGenerator
     cmXCodeObject* t = *i;
     this->AddDependAndLinkInformation(t);
     }
-  // now create xcode depend hack makefile
-  this->CreateXCodeDependHackTarget(targets);
+  if(this->XcodeVersion < 50)
+    {
+    // now create xcode depend hack makefile
+    this->CreateXCodeDependHackTarget(targets);
+    }
   // now add all targets to the root object
   cmXCodeObject* allTargets = this->CreateObject(cmXCodeObject::OBJECT_LIST);
   for(std::vector<cmXCodeObject*>::iterator i = targets.begin();