Add ext_backslash_newline_eof to Wnewline-eof group.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135830 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticLexKinds.td b/include/clang/Basic/DiagnosticLexKinds.td
index b939122..d260d31 100644
--- a/include/clang/Basic/DiagnosticLexKinds.td
+++ b/include/clang/Basic/DiagnosticLexKinds.td
@@ -40,7 +40,8 @@
   InGroup<Comment>;
 def ext_no_newline_eof : Extension<"no newline at end of file">, 
   InGroup<DiagGroup<"newline-eof">>;
-def ext_backslash_newline_eof : Extension<"backslash-newline at end of file">;
+def ext_backslash_newline_eof : Extension<"backslash-newline at end of file">,
+  InGroup<DiagGroup<"newline-eof">>;
 def ext_dollar_in_identifier : Extension<"'$' in identifier">;
 def charize_microsoft_ext : Extension<"@# is a microsoft extension">;