enable __has_feature(is_standard_layout)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@131240 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 2d04d77..ce7acf7 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -593,6 +593,7 @@
            .Case("is_empty", LangOpts.CPlusPlus)
            .Case("is_enum", LangOpts.CPlusPlus)
            .Case("is_literal", LangOpts.CPlusPlus)
+           .Case("is_standard_layout", LangOpts.CPlusPlus)
            .Case("is_pod", LangOpts.CPlusPlus)
            .Case("is_polymorphic", LangOpts.CPlusPlus)
            .Case("is_trivial", LangOpts.CPlusPlus)