clang-format: Fix incorrect enum parsing / layouting.

Before:
  enum {
    Bar = Foo < int,
    int > ::value
  };

After:
  enum {
    Bar = Foo<int, int>::value
  };

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190674 91177308-0d34-0410-b5e6-96231b3b80d8