clang-format: Understand more lambda return types.

Before:
  auto a = [&b, c ](D * d) -> D * {}

After:
 auto a = [&b, c](D* d) -> D* {}

llvm-svn: 222534
diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index af1e94c..2c6a4fb 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -867,6 +867,9 @@
     case tok::l_paren:
       parseParens();
       break;
+    case tok::amp:
+    case tok::star:
+    case tok::kw_const:
     case tok::less:
     case tok::greater:
     case tok::identifier: