Linking objects built with MingW on windows

[ronnie-w]

I tried linking an object built with MingW with the command
```
g++ -c libs/webview/webview.cc --std=c++14 -Ilibs/webview2 
-DWEBVIEW_STATIC -mwindows -static-libgcc -static-libstdc++ -o 
webview.o

```
In my source root dir, I tried:
```
dmd app.d .\webview.d .\webview.o advapi32.lib ole32.lib 
shell32.lib shlwapi.lib user32.lib version.lib -extern-std=c++14

```
But most of the errors I get (from lld-link.exe) seem to stem 
from undefined symbols from c++11:
```
lld-link: error: undefined symbol: 
_ZTVN10__cxxabiv117__class_type_infoE
>>> referenced by 
>>> .\webview.obj:(_ZTIZZ12webview_bindENKUlvE_clEvEUlRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES7_PvE_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZZ16webview_dispatchENKUlvE_clEvEUlvE_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZN7webview6detail11engine_base10on_messageERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEUlvE_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZN7webview6detail11engine_base28deplete_run_loop_event_queueEvEUlvE_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZN7webview6detail11engine_base28deplete_run_loop_event_queueEvEUlvE0_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZN7webview6detail11engine_base21dispatch_size_defaultEvEUlvE_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZN7webview6detail17win32_edge_engine20add_user_script_implERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEUllPKwE_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZN7webview6detail17win32_edge_engine20add_user_script_implERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEUlvE_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZN7webview6detail17win32_edge_engine20add_user_script_implERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEUlPNS0_11user_script4implEE_)
>>> referenced by 
>>> .\webview.obj:(_ZTIZN7webview6detail17win32_edge_engine5embedEP6HWND__bSt8functionIFvNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEEUlP23ICoreWebView2ControllerP13ICoreWebView2E_)
>>> referenced 7 more times

lld-link: error: undefined symbol: 
_ZTVN10__cxxabiv120__si_class_type_infoE
>>> referenced by .\webview.obj:(_ZTIN7webview9exceptionE)
>>> referenced by 
>>> .\webview.obj:(_ZTISt5_BindIFZN7webview6detail11engine_base7resolveERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiSA_EUlS8_E_S8_EE)
>>> referenced by 
>>> .\webview.obj:(_ZTISt5_BindIFMN7webview6detail11engine_baseEFvRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEPNS1_17win32_edge_engineESt12_PlaceholderILi1EEEE)
>>> referenced by 
>>> .\webview.obj:(_ZTIN7webview6detail10bad_accessE)
>>> referenced by 
>>> .\webview.obj:(_ZTIN7webview6detail17win32_edge_engineE)
>>> referenced by 
>>> .\webview.obj:(_ZTIN7webview6detail34webview2_user_script_added_handlerE)
>>> referenced by 
>>> .\webview.obj:(_ZTI57ICoreWebView2CreateCoreWebView2ControllerCompletedHandler)
>>> referenced by 
>>> .\webview.obj:(_ZTI58ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler)
>>> referenced by 
>>> .\webview.obj:(_ZTI64ICoreWebView2AddScriptToExecuteOnDocumentCreatedCompletedHandler)
>>> referenced by 
>>> .\webview.obj:(_ZTI43ICoreWebView2WebMessageReceivedEventHandler)
>>> referenced 5 more times

and much much more ...

```

... and also from ldc2:
```
lld-link: error: undefined symbol: vtable for 
__cxxabiv1::__class_type_info
>>> referenced by .\webview.obj:(typeinfo for 
>>> webview_bind::'lambda'()::operator()() 
>>> const::'lambda'(std::__cxx11::basic_string<char, 
>>> std::char_traits<char>, std::allocator<char>> const&, 
>>> std::__cxx11::basic_string<char, std::char_traits<char>, 
>>> std::allocator<char>> const&, void*))
>>> referenced by .\webview.obj:(typeinfo for 
>>> webview_dispatch::'lambda'()::operator()() const::'lambda'())
>>> referenced by .\webview.obj:(typeinfo for 
>>> webview::detail::engine_base::on_message(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>> const&)::'lambda'())
>>> referenced 14 more times

lld-link: error: undefined symbol: vtable for 
__cxxabiv1::__si_class_type_info
>>> referenced by .\webview.obj:(typeinfo for webview::exception)
>>> referenced by .\webview.obj:(typeinfo for 
>>> std::_Bind<webview::detail::engine_base::resolve(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>> const&, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>> const&)::'lambda'(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>) (std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>)>)
>>> referenced by .\webview.obj:(typeinfo for std::_Bind<void 
>>> (webview::detail::engine_base::* 
>>> (webview::detail::win32_edge_engine*, 
>>> std::_Placeholder<1>))(std::__cxx11::basic_string<char, 
>>> std::char_traits<char>, std::allocator<char>> const&)>)
>>> referenced 12 more times
...
```

I've tried changing extern-std to c++11 but it also fails. I've 
also tried linking with libstd++ from my local MingW installation 
but I get something along the lines of
```
duplicate symbol: ___xxx___xxxxx
    libstdc++
```

Building the g++ as a standalone exe with the libs `advapi32.lib 
ole32.lib shell32.lib shlwapi.lib user32.lib version.lib` and 
`--std=c++14` produces an exe that works as expected.

I'm probably doing the linking wrong.