[C++11] Replace LLVM-style type traits with C++11 standard ones.

No functionality change.

llvm-svn: 203241
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 6eaf140..1a8748c 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -29,7 +29,6 @@
 #include "clang/Basic/Specifiers.h"
 #include "clang/Basic/TargetInfo.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/type_traits.h"
 #include <algorithm>
 
 using namespace clang;
@@ -158,8 +157,7 @@
 /// Does the given declaration have member specialization information,
 /// and if so, is it an explicit specialization?
 template <class T> static typename
-llvm::enable_if_c<!llvm::is_base_of<RedeclarableTemplateDecl, T>::value,
-                  bool>::type
+std::enable_if<!std::is_base_of<RedeclarableTemplateDecl, T>::value, bool>::type
 isExplicitMemberSpecialization(const T *D) {
   if (const MemberSpecializationInfo *member =
         D->getMemberSpecializationInfo()) {