clang-format: Understand function type typedefs with typeof.

Before:
  typedef typeof(int(int, int)) * MyFunc;
After:
  typedef typeof(int(int, int)) *MyFunc;

This fixes llvm.org/PR17178.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190401 91177308-0d34-0410-b5e6-96231b3b80d8