Index: clang/lib/Lex/LiteralSupport.cpp
===================================================================
--- clang/lib/Lex/LiteralSupport.cpp
+++ clang/lib/Lex/LiteralSupport.cpp
@@ -653,7 +653,7 @@
         }
       }
       // "i", "if", and "il" are user-defined suffixes in C++1y.
-      if (*s == 'i' && PP.getLangOpts().CPlusPlus14)
+      if (*s == 'i' && !PP.getLangOpts().GNUMode)
         break;
       // fall through.
     case 'j':
Index: clang/test/SemaCXX/constexpr-printing.cpp
===================================================================
--- clang/test/SemaCXX/constexpr-printing.cpp
+++ clang/test/SemaCXX/constexpr-printing.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -std=c++11 -fsyntax-only -verify -triple x86_64-linux-gnu
+// RUN: %clang_cc1 %s -std=gnu++11 -fsyntax-only -verify -triple x86_64-linux-gnu
 
 struct S;
 constexpr int extract(const S &s);
Index: clang/unittests/AST/DeclTest.cpp
===================================================================
--- clang/unittests/AST/DeclTest.cpp
+++ clang/unittests/AST/DeclTest.cpp
@@ -26,7 +26,7 @@
   // This is a regression test for a memory leak in APValues for structs that
   // allocate memory. This test only fails if run under valgrind with full leak
   // checking enabled.
-  std::vector<std::string> Args(1, "-std=c++11");
+  std::vector<std::string> Args(1, "-std=gnu++11");
   Args.push_back("-fno-ms-extensions");
   ASSERT_TRUE(runToolOnCodeWithArgs(
       Factory->create(),