Failed to select_overload when template function have a typename after a variadic typename

Please consider the following example. I made an example more and more complex. The goal is to be able to bind `struct S5` but at the current time, I can't bind `struct S4` when the template is `` with the `U` auto-deduced.

Do you have an idea ? Or is it a limitation of bind.h ? Any workaround ?
Thanks,

```
#include

using namespace emscripten;

struct S {
void f() const {}
};

struct S2 {
template
void f() const {}
};

struct S3 {
template
void f() const {}
};

struct S4 {
template
void f(U) const {}
};

struct S5 {
template
void f(U...) const {}
};

EMSCRIPTEN_BINDINGS(jessica) {
class_("S").function("f", select_overload(&S::f));

class_("S2").function("f2", select_overload(&S2::f));

class_("S3").function("f3",
select_overload(&S3::f));

// BAD1: auto deduce char.
//class_("S4").function(
// "f4", select_overload(&S4::f));
/*
/root/prog/emscripten/emsdk/upstream/emscripten/cache/sysroot/include/emscripten/bind.h:306:6: note: candidate template ignored: couldn't infer template argument 'ClassType'
auto select_overload(Signature (ClassType::*fn)) -> decltype(fn) {
^
/root/prog/emscripten/emsdk/upstream/emscripten/cache/sysroot/include/emscripten/bind.h:301:12: note: candidate template ignored: substitution failure [with Signature = void (char) const]: pointer to function type 'void (char) const' cannot have 'const' qualifier
Signature* select_overload(Signature* fn) {
~~~~~~~~~ ^
*/

// BAD2: explicit template char.
class_("S4").function(
"f4", select_overload(&S4::f));
/*
/root/prog/emscripten/emsdk/upstream/emscripten/cache/sysroot/include/emscripten/bind.h:306:6: note: candidate template ignored: couldn't infer template argument 'ClassType'
auto select_overload(Signature (ClassType::*fn)) -> decltype(fn) {
^
/root/prog/emscripten/emsdk/upstream/emscripten/cache/sysroot/include/emscripten/bind.h:301:12: note: candidate template ignored: substitution failure [with Signature = void (char) const]: pointer to function type 'void (char) const' cannot have 'const' qualifier
Signature* select_overload(Signature* fn) {
~~~~~~~~~ ^
*/
}
```

Build it with:
`emcc main.cpp -o output.js -s MODULARIZE=1 --bind -s EXPORT_NAME=ModuleTest`