Switch to gnu++14 as the default dialect.

This is C++14 with conforming GNU extensions.

llvm-svn: 320250
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 59e5b62..2ebdc2a 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1729,11 +1729,7 @@
       break;
     case InputKind::CXX:
     case InputKind::ObjCXX:
-      // The PS4 uses C++11 as the default C++ standard.
-      if (T.isPS4())
-        LangStd = LangStandard::lang_gnucxx11;
-      else
-        LangStd = LangStandard::lang_gnucxx98;
+      LangStd = LangStandard::lang_gnucxx14;
       break;
     case InputKind::RenderScript:
       LangStd = LangStandard::lang_c99;