clang-format: Correct SBPO_Always-behavior after function-like keywords

Before:
  auto f (int x) -> decltype(x) { return sizeof(x); }
  int g () noexcept(someCall ());
  static_assert(sizeof(char) == 1, "Your compiler is broken");

After:
  auto f (int x) -> decltype (x) { return sizeof (x); }
  int g () noexcept (someCall ());
  static_assert (sizeof (char) == 1, "Your compiler is broken");

This fixes llvm.org/PR20559.
Patch by Roman Kashitsyn, thank you!

llvm-svn: 214969