Function MakePolymorphicMatcher

tests/gtest/gtest.h:9416–9418

//   PolymorphicMatcher<TypeOfFoo>(foo);
template <class Impl>
inline PolymorphicMatcher<Impl> MakePolymorphicMatcher(const Impl& impl) {
  return PolymorphicMatcher<Impl>(impl);
}

namespace internal {
// Implements a matcher that compares a given value with a