Fix incorrect detection of class definitions with alignas specification.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192094 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/UnwrappedLineParser.cpp b/lib/Format/UnwrappedLineParser.cpp
index 605aeba..d8aa3f3 100644
--- a/lib/Format/UnwrappedLineParser.cpp
+++ b/lib/Format/UnwrappedLineParser.cpp
@@ -1069,7 +1069,8 @@
   nextToken();
   if (FormatTok->Tok.is(tok::identifier) ||
       FormatTok->Tok.is(tok::kw___attribute) ||
-      FormatTok->Tok.is(tok::kw___declspec)) {
+      FormatTok->Tok.is(tok::kw___declspec) ||
+      FormatTok->Tok.is(tok::kw_alignas)) {
     nextToken();
     // We can have macros or attributes in between 'class' and the class name.
     if (FormatTok->Tok.is(tok::l_paren)) {