_memsetFloat Error with dmd

[Maximilian Naderer]

Hello people,

i have the following example. Compiled with dmd and ldc2

dmd main.d -betterC
ldc2 main.d -betterC

with dmd the compilation fails with

     lld-link: error: undefined symbol: _memsetFloat
     >>> referenced by app.obj:(main)
     Error: linker exited with status 1
            C:\dev\dlang\dmd2\windows\bin64\lld-link.exe /NOLOGO 
"app.obj"    
/LIBPATH:"C:\dev\dlang\dmd2\windows\bin64\..\lib64\mingw

The compilation fails only with dmd when I'm not assigning all 
the fields of a struct like in example #3. Is this a compiler 
error ?

```d
struct MyStruct {
     float[4] data;
     float[16] matrix;
}

extern(C) int main() {


     MyStruct sWorks = MyStruct(
         data: [1.0f, 2.0f, 3.0f, 4.0f],
         matrix: [
             1.0f, 0.0f, 0.0f, 0.0f,
             0.0f, 1.0f, 0.0f, 0.0f,
             0.0f, 0.0f, 1.0f, 0.0f,
             0.0f, 0.0f, 0.0f, 1.0f
         ]);

     MyStruct sWorks2;
     sWorks2.data = [ 1.0f, 0.0f, 0.0f, 1.0f ];

     MyStruct sNotWorking = MyStruct(
         data: [ 1.0f, 0.0f, 0.0f, 1.0f ],
         matrix: [
             1.0f, 0.0f, 0.0f, 0.0f,
             0.0f, 1.0f, 0.0f, 0.0f,
             0.0f, 0.0f, 1.0f, 0.0f,
             0.0f, 0.0f, 0.0f, 1.0f
         ]);


     return 0;
}
```