clang-format: Support member function reference qualifiers.

Before:
  string // break
      operator()() &
  {}

After:
  string // break
  operator()() & {}

llvm-svn: 212041
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 75eea98..96274fc 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -4682,6 +4682,11 @@
   verifyFormat("Deleted &operator=(const Deleted &)&& = delete;");
   verifyGoogleFormat("Deleted& operator=(const Deleted&)& = default;");
   verifyGoogleFormat("Deleted& operator=(const Deleted&)&& = delete;");
+
+  verifyFormat("string // break\n"
+               "operator()() & {}");
+  verifyFormat("string // break\n"
+               "operator()() && {}");
 }
 
 TEST_F(FormatTest, UnderstandsNewAndDelete) {