clang-format: Properly parse parenthesis in braced lists.

Among other things, this makes clang-format understand arbitrary blocks
embedded in them, such as:

  SomeFunction({MACRO({ return output; }), b});

where MACRO could e.g. expand to a lambda.

llvm-svn: 241059
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 743171f..ef5299a 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -3184,6 +3184,8 @@
                "}, a);",
                Style);
 
+  verifyFormat("SomeFunction({MACRO({ return output; }), b});");
+
   verifyNoCrash("^{v^{a}}");
 }