How do I define pragma(mangle,"name") for a type?
Use case:
I'd like to avoid the complications involved in
https://github.com/dlang/druntime/pull/1316/files [Addition of C++
std::string, std::vector to D #1316]
by directly defining the desired mangle for a c++ std::string (+ other
similar use cases):
```
pragma(mangle, "NSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE")
struct string_cpp;
extern(C++, ns){
void fun1(string_cpp*a);
string_cpp fun2();
void string_cpp fun3(const ref string_cpp a);
}
```
The problem is that this mangles fun1 as _ZN2ns4fun1EP10string_cpp , ie,
using "string_cpp" instead of
"NSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE" for the `a` argument
of fun1, thus ignoring (silently!) the pragma(mangle).
