clang-format: Improve detection of templates.

Before:
  template <typename... Types>
        typename enable_if < 0<sizeof...(Types)>::type Foo() {}
After:
  template <typename... Types>
  typename enable_if<0 < sizeof...(Types)>::type Foo() {}

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187458 91177308-0d34-0410-b5e6-96231b3b80d8