[C++ interop] Cannot provide release/retain funcs for template class

[ktoso]

rdar://103106740

Let's say I have CoolVar<T>:

#define SWIFT_CXX_REF_COOLVAR   					\
    __attribute__((swift_attr("import_as_ref")))   	\
    __attribute__((swift_attr("retain:retain_CoolVar")))   \
    __attribute__((swift_attr("release:release_CoolVar")))

template <class V>
class SWIFT_CXX_REF_COOLVAR CoolVar : public ReferenceCounted<CoolVar<V>> { }

It seems we don't fine the templated functions:

template <class V>
inline void retain_CoolVar(CoolVar <V>* ptr) {
  // ... 
}

template <class V>
inline void release_CoolVar(CoolVar <V>* ptr) {
  // ... 
}

error being:

error: cannot find retain function 'retain_ CoolVar' for reference type 'CoolVar'.

[ktoso]

I'm dumb, we track this already: #61620